Mary Shelley (née Mary Wollstonecraft Godwin; 30 August 1797 – 1 February 1851) was a British novelist, short story writer, dramatist, essayist, biographer, and travel writer, best known for her Gothic novel Frankenstein: or, The Modern Prometheus (1818). She also edited and promoted the works of her husband, the Romantic poet and philosopher Percy Bysshe Shelley. Her father was the political philosopher William Godwin, and her mother was the philosopher and feminist Mary Wollstonecraft.

Mary Godwin's mother died when she was eleven days old; afterwards, she and her older half-sister, Fanny Imlay, were raised by her father. When Mary was four, Godwin married his neighbour, Mary Jane Clairmont. Godwin provided his daughter with a rich, if informal, education, encouraging her to adhere to his liberal political theories. In 1814, Mary Godwin began a romantic relationship with one of her father’s political followers, the married Percy Bysshe Shelley. Together with Mary's stepsister, Claire Clairmont, they left for France and travelled through Europe; upon their return to England, Mary was pregnant with Percy's child. Over the next two years, she and Percy faced ostracism, constant debt, and the death of their prematurely born daughter. They married in late 1816 after the suicide of Percy Shelley's first wife, Harriet.

In 1816, the couple famously spent a summer with Lord Byron, John William Polidori, and Claire Clairmont near Geneva, Switzerland, where Mary conceived the idea for her novel Frankenstein. The Shelleys left Britain in 1818 for Italy, where their second and third children died before Mary Shelley gave birth to her last and only surviving child, Percy Florence. In 1822, her husband drowned when his sailing boat sank during a storm in the Bay of La Spezia. A year later, Mary Shelley returned to England and from then on devoted herself to the upbringing of her son and a career as a professional author. The last decade of her life was dogged by illness, probably caused by the brain tumour that was to kill her at the age of 53.

Until the 1970s, Mary Shelley was known mainly for her efforts to publish Percy Shelley's works and for her novel Frankenstein, which remains widely read and has inspired many theatrical and film adaptations. Recent scholarship has yielded a more comprehensive view of Mary Shelley’s achievements. Scholars have shown increasing interest in her literary output, particularly in her novels, which include the historical novels Valperga (1823) and Perkin Warbeck (1830), the apocalyptic novel The Last Man (1826), and her final two novels, Lodore (1835) and Falkner (1837). Studies of her lesser known works such as the travel book Rambles in Germany and Italy (1844) and the biographical articles for Dionysius Lardner's Cabinet Cyclopaedia (1829–46) support the growing view that Mary Shelley remained a political radical throughout her life. Mary Shelley's works often argue that cooperation and sympathy, particularly as practised by women in the family, were the ways to reform civil society. This view was a direct challenge to the individualistic Romantic ethos promoted by Percy Shelley and the Enlightenment political theories articulated by her father, William Godwin.

Mary Shelley was born Mary Wollstonecraft Godwin in Somers Town, London, in 1797. She was the second child of the feminist philosopher, educator, and writer Mary Wollstonecraft, and the first child of the philosopher, novelist, and journalist William Godwin. Wollstonecraft died of puerperal fever ten days after Mary was born. Godwin was left to bring up Mary, along with her older half-sister, Fanny Imlay, Wollstonecraft's child by the American speculator Gilbert Imlay. A year after Wollstonecraft's death, Godwin published his Memoirs of the Author of A Vindication of the Rights of Woman (1798), which he intended as a sincere and compassionate tribute. However, because the Memoirs revealed Wollstonecraft's affairs and her illegitimate child, they were seen as shocking. Mary Godwin read these memoirs and her mother's books, and was brought up to cherish her mother's memory.

Mary's earliest years were happy ones, judging from the letters of William Godwin's housekeeper and nurse, Louisa Jones. But Godwin was often deeply in debt; feeling that he could not raise the children by himself, he cast about for a second wife. In December 1801, he married Mary Jane Clairmont, a well-educated woman with two young children of her own — Charles and Claire. Most of Godwin’s friends disliked his new wife, describing her as quick-tempered and quarrelsome; but Godwin was devoted to her, and the marriage was a success. Mary Godwin, on the other hand, came to detest her stepmother. William Godwin's 19th-century biographer C. Kegan Paul later suggested that Mrs Godwin had favoured her own children over Mary Wollstonecraft’s.

Together, the Godwins started a publishing firm called M.J. Godwin, which sold children's books as well as stationery, maps, and games. However, the business did not turn a profit, and Godwin was forced to borrow substantial sums to keep it going. He continued to borrow to pay off earlier loans, compounding his problems. By 1809, Godwin's business was close to failure and he was "near to despair". Godwin was saved from debtor's prison by philosophical devotees such as Francis Place, who lent him further money.

Though Mary Godwin received little formal education, her father tutored her in a broad range of subjects. He often took the children on educational outings, and they had access to his library and to the many intellectuals who visited him, including the Romantic poet Samuel Taylor Coleridge and the former vice-president of the United States Aaron Burr. Godwin admitted he was not educating the children according to Mary Wollstonecraft's philosophy as outlined in works such as A Vindication of the Rights of Woman (1792), but Mary Godwin nonetheless received an unusual and advanced education for a girl of the time. She had a governess, a daily tutor, and read many of her father's children's books on Roman and Greek history in manuscript. For six months in 1811, she also attended a boarding school in Ramsgate. Her father described her at fifteen as "singularly bold, somewhat imperious, and active of mind. Her desire of knowledge is great, and her perseverance in everything she undertakes almost invincible."

In June 1812, her father sent Mary to stay with the Dissenting family of the radical William Baxter, near Dundee, Scotland. To Baxter, he wrote, "I am anxious that she should be brought up ... like a philosopher, even like a cynic." Scholars have speculated that she may have been sent away for her health, to remove her from the seamy side of business, or to introduce her to radical politics. Mary Godwin revelled in the spacious surroundings of Baxter's house and in the companionship of his four daughters, and she returned north in the summer of 1813 for a further stay of ten months. In the 1831 introduction to Frankenstein, she recalled: "I wrote then — but in a most common-place style. It was beneath the trees of the grounds belonging to our house, or on the bleak sides of the woodless mountains near, that my true compositions, the airy flights of my imagination, were born and fostered."

Mary Godwin may have first met the radical poet-philosopher Percy Bysshe Shelley in the interval between her two stays in Scotland. By the time she returned home for a second time on 30 March 1814, Percy Shelley had become estranged from his wife and was regularly visiting Godwin, whom he had agreed to bail out of debt. Percy Shelley's radicalism, particularly his economic views, which he had imbibed from Godwin's Political Justice (1793), had alienated him from his wealthy aristocratic family: they wanted him to follow traditional models of the landed aristocracy, and he wanted to donate large amounts of the family's money to schemes intended to help the disadvantaged. Percy Shelley therefore had difficulty gaining access to money until he inherited his estate because his family did not want him wasting it on projects of "political justice". After several months of promises, Shelley announced that he either could not or would not pay off all of Godwin's debts. Godwin was angry and felt betrayed.

Mary and Percy began meeting each other secretly at Mary Wollstonecraft's grave in St Pancras Churchyard, and they fell in love — she was nearly seventeen, he nearly twenty-two. To Mary's dismay, her father disapproved and tried to thwart the relationship and salvage the "spotless fame" of his daughter. At about the same time, Godwin learned of Shelley's inability to pay off his loans for him. Mary, who later wrote of "my excessive and romantic attachment to my father", was confused. She saw Percy Shelley as an embodiment of her parents' liberal and reformist ideas of the 1790s, particularly Godwin's view that marriage was a repressive monopoly, which he had argued in his 1793 edition of Political Justice but since retracted. On 28 July 1814, the couple secretly left for France, taking Mary's stepsister, Claire Clairmont, with them, but leaving Percy's pregnant wife behind. After convincing Mary Jane Godwin, who had pursued them to Calais, that they did not wish to return, the trio travelled to Paris, and then, by donkey, mule, and carriage, through a France recently ravaged by war, to Switzerland. "It was acting in a novel, being an incarnate romance," Mary Shelley recalled in 1826. As they travelled, Mary and Percy read works by Mary Wollstonecraft and others, kept a joint journal, and continued their own writing. At Lucerne, lack of money forced the three to turn back. They travelled down the Rhine and by land to the Dutch port of Marsluys, arriving at Gravesend, Kent, on 13 September 1814.

The situation awaiting Mary Godwin in England was fraught with complications, some of which she had not foreseen. Either before or during the journey, she had become pregnant. She and Percy now found themselves penniless, and, to Mary's genuine surprise, her father refused to have anything to do with her. The couple moved with Claire into lodgings at Somers Town, and later, Nelson Square. They maintained their intense programme of reading and writing and entertained Percy Shelley's friends, such as Thomas Jefferson Hogg and the writer Thomas Love Peacock. Percy Shelley sometimes left home for short periods to dodge creditors. The couple's distraught letters reveal their pain at these separations. Pregnant and often ill, Mary Godwin had to cope with Percy's joy at the birth of his son by Harriet Shelley in late 1814 and his constant outings with Claire Clairmont. She was partly consoled by the visits of Hogg, whom she disliked at first but soon considered a close friend. Percy Shelley seems to have wanted Mary Godwin and Hogg to become lovers; Mary did not dismiss the idea, since in principle she believed in free love. In practice, however, she loved only Percy Shelley and seems to have ventured no further than flirting with Hogg. On 22 February 1815, she gave birth to a two-months premature baby girl, who was not expected to survive. On 6 March, she wrote to Hogg:

My dearest Hogg my baby is dead — will you come to see me as soon as you can. I wish to see you — It was perfectly well when I went to bed — I awoke in the night to give it suck it appeared to be sleeping so quietly that I would not awake it. It was dead then, but we did not find that out till morning — from its appearance it evidently died of convulsions — Will you come — you are so calm a creature & Shelley is afraid of a fever from the milk — for I am no longer a mother now.

The loss of her child induced acute depression in Mary Godwin, who was haunted by visions of the baby; but she conceived again and had recovered by the summer. With a revival in Percy Shelley's finances after the death of his grandfather, Sir Bysshe Shelley, the couple holidayed in Torquay and then rented a two-storey cottage at Bishopsgate, on the edge of Windsor Great Park. Little is known about this period in Mary Godwin's life, since her journal from May 1815 to July 1816 is lost. At Bishopsgate, Percy wrote his poem Alastor; and on 24 January 1816, Mary gave birth to a second child, William, named after her father and soon nicknamed "Willmouse". In her novel The Last Man, she later imagined Windsor as a Garden of Eden.

In May 1816, Mary Godwin, Percy Shelley, and their son travelled to Geneva with Claire Clairmont. They planned to spend the summer with the poet Lord Byron, whose recent affair with Claire had left her pregnant. The party arrived at Geneva on 14 May 1816, where Mary called herself "Mrs Shelley". Byron joined them on 25 May, with his young physician, John William Polidori, and rented the Villa Diodati, close to Lake Geneva at the village of Cologny; Percy Shelley rented a smaller building called Maison Chapuis on the waterfront nearby. They spent their time writing, boating on the lake, and talking late into the night.

"It proved a wet, ungenial summer", Mary Shelley remembered in 1831, "and incessant rain often confined us for days to the house". Amongst other subjects, the conversation turned to the experiments of the 18th-century natural philosopher and poet Erasmus Darwin, who was said to have animated dead matter, and to galvanism and the feasibility of returning a corpse or assembled body parts to life. Sitting around a log fire at Byron's villa, the company also amused themselves by reading German ghost stories, prompting Byron to suggest they each write their own supernatural tale. Shortly afterwards, in a waking dream, Mary Godwin conceived the idea for Frankenstein:

I saw the pale student of unhallowed arts kneeling beside the thing he had put together. I saw the hideous phantasm of a man stretched out, and then, on the working of some powerful engine, show signs of life, and stir with an uneasy, half vital motion. Frightful must it be; for supremely frightful would be the effect of any human endeavour to mock the stupendous mechanism of the Creator of the world.

She began writing what she assumed would be a short story. With Percy Shelley's encouragement, she expanded this tale into her first novel, Frankenstein: or, The Modern Prometheus, published in 1818. She later described that summer in Switzerland as the moment "when I first stepped out from childhood into life".

On their return to England in September, Mary and Percy moved — with Claire Clairmont, who took lodgings nearby — to Bath, where they hoped to keep Claire’s pregnancy secret. At Cologny, Mary Godwin had received two letters from her half-sister, Fanny Imlay, who alluded to her "unhappy life"; on 9 October, Fanny wrote an "alarming letter" from Bristol that sent Percy Shelley racing off to search for her, without success. On the morning of 10 October, Fanny Imlay was found dead in a room at a Swansea inn, along with a suicide note and a laudanum bottle. On 10 December, Percy Shelley's wife, Harriet, was discovered drowned in the Serpentine, a lake in Hyde Park, London. Both suicides were hushed up. Harriet’s family obstructed Percy Shelley's efforts — fully supported by Mary Godwin — to assume custody of his two children by Harriet. His lawyers advised him to improve his case by marrying; so he and Mary, who was pregnant again, married on 30 December 1816 at St Mildred's Church, Bread Street, London. Mr and Mrs Godwin were present and the marriage ended the family rift.

Claire Clairmont gave birth to a baby girl on 13 January, at first called Alba, later Allegra. In March of that year, the Chancery Court ruled Percy Shelley morally unfit to assume custody of his children and later placed them with a clergyman's family. Also in March, the Shelleys moved with Claire and Alba to Albion House at Marlow, Buckinghamshire, a large, damp building on the river Thames. There Mary Shelley gave birth to her third child, Clara, on 2 September. At Marlow, they entertained their new friends Marianne and Leigh Hunt, worked hard at their writing, and often discussed politics.

Early in the summer of 1817, Mary Shelley finished Frankenstein, which was published anonymously in January 1818. Reviewers and readers assumed that Percy Shelley was the author, since the book was published with his preface and dedicated to his political hero William Godwin. At Marlow, Mary edited the joint journal of the group's 1814 Continental journey, adding material written in Switzerland in 1816, along with Percy's poem "Mont Blanc". The result was the History of a Six Weeks' Tour, published in November 1817. That autumn, Percy Shelley often lived away from home in London to evade creditors. The threat of a debtor's prison, combined with their ill health and fears of losing custody of their children, contributed to the couple's decision to leave England for Italy on 12 March 1818, taking Claire Clairmont and Alba with them. They had no intention of returning.

One of the party's first tasks on arriving in Italy was to hand Alba over to Byron, who was living in Venice. He had agreed to raise her so long as Claire had nothing more to do with her. The Shelleys then embarked on a roving existence, never settling in any one place for long. Along the way, they accumulated a circle of friends and acquaintances who often moved with them. The couple devoted their time to writing, reading, learning, sightseeing, and socialising. The Italian adventure was, however, blighted for Mary Shelley by the deaths of both her children — Clara, in September 1818 in Venice, and William, in June 1819 in Rome. These losses left her in a deep depression that isolated her from Percy Shelley, who wrote in his notebook:

My dearest Mary, wherefore hast thou gone,

And left me in this dreary world alone?

Thy form is here indeed — a lovely one —

But thou art fled, gone down a dreary road

That leads to Sorrow’s most obscure abode.

For thine own sake I cannot follow thee

Do thou return for mine.

For a time, Mary Shelley found comfort only in her writing. The birth of her fourth child, Percy Florence, on 12 November 1819, finally lifted her spirits, though she nursed the memory of her lost children till the end of her life.

Italy provided the Shelleys, Byron, and other exiles with a political freedom unattainable at home. Despite its associations with personal loss, Italy became for Mary Shelley "a country which memory painted as paradise". Their Italian years were a time of intense intellectual and creative activity for both Shelleys. While Percy composed a series of major poems, Mary wrote the autobiographical novel Matilda, the historical novel Valperga, and the plays Proserpine and Midas. Mary wrote Valperga to help alleviate her father's financial difficulties, as Percy refused to assist him further. She was often physically ill, however, and prone to depressions. She also had to cope with Percy’s interest in other women, such as Sophia Stacey, Emilia Viviani, and Jane Williams. Since Mary Shelley shared his belief in the non-exclusivity of marriage, she formed emotional ties of her own among the men and women of their circle. She became particularly fond of the Greek revolutionary Prince Alexander Mavrocordato and of Jane and Edward Williams.

In December 1818, the Shelleys travelled south with Claire Clairmont and their servants to Naples, where they stayed for three months, receiving only one visitor, a physician. In 1820, they found themselves plagued by accusations and threats from Paolo and Elise Foggi, former servants whom Percy Shelley had dismissed in Naples shortly after the Foggis had married. The pair revealed that on 27 February 1819 in Naples, Percy Shelley had registered as his child by Mary Shelley a two-month-old baby girl named Elena Adelaide Shelley. The Foggis also claimed that Claire Clairmont was the baby's mother. Biographers have offered various interpretations of these events: that Percy Shelley decided to adopt a local child; that the baby was his by Elise, Claire, or an unknown woman; or that she was Elise’s by Byron. Mary Shelley insisted she would have known if Claire had been pregnant, but it is unclear how much she really knew. The events in Naples, a city Mary Shelley later called a paradise inhabited by devils, remain shrouded in mystery. The only certainty is that she herself was not the child’s mother. Elena Adelaide Shelley died in Naples on 9 June 1820.

In the summer of 1822, a pregnant Mary moved with Percy, Claire, and Edward and Jane Williams to the isolated Villa Magni, at the sea's edge near the hamlet of San Terenzo in the Bay of Lerici. Once they were settled in, Percy broke the "evil news" to Claire that her daughter Allegra had died of typhus in a convent at Bagnacavallo. Mary Shelley was distracted and unhappy in the cramped and remote Villa Magni, which she came to regard as a dungeon. On 16 June, she miscarried, losing so much blood that she nearly died. Rather than wait for a doctor, Percy sat her in a bath of ice to staunch the bleeding, an act the doctor later told him saved her life. All was not well between the couple that summer, however, and Percy spent more time with Jane Williams than with his depressed and debilitated wife. Most of the short poems Shelley wrote at San Terenzo were addressed to Jane rather than to Mary.

The coast offered Percy Shelley and Edward Williams the chance to enjoy their "perfect plaything for the summer", a new sailing boat. The boat had been designed by Daniel Roberts and Edward Trelawny, an admirer of Byron's who had joined the party in January 1822. On 1 July 1822, Percy Shelley, Edward Ellerker Williams, and Captain Daniel Roberts sailed south down the coast to Livorno. There Percy Shelley discussed with Byron and Leigh Hunt the launch of a radical magazine called The Liberal. On 8 July, he and Edward Williams set out on the return journey to Lerici with their eighteen-year-old boatboy, Charles Vivian. They never reached their destination. A letter arrived at Villa Magni from Hunt to Percy Shelley, dated 8 July, saying, "pray write to tell us how you got home, for they say you had bad weather after you sailed monday & we are anxious". "The paper fell from me," Mary told a friend later. "I trembled all over." She and Jane Williams rushed desperately to Livorno and then to Pisa in the fading hope that their husbands were still alive. Ten days after the storm, three bodies washed up on the coast near Viareggio, midway between Livorno and Lerici. Trelawny, Byron, and Hunt cremated Percy Shelley’s corpse on the beach at Viareggio.

After her husband's death, Mary Shelley lived for a year with Leigh Hunt and his family in Genoa, where she often saw Byron and transcribed his poems. She resolved to live by her pen and for her son, but her financial situation was precarious. On 23 July 1823, she left Genoa for England and stayed with her father and stepmother in the Strand until a small advance from her father-in-law enabled her to lodge nearby. Sir Timothy Shelley had at first agreed to support his grandson, Percy Florence, only if he were handed over to an appointed guardian. Mary Shelley rejected this idea instantly. She managed instead to wring out of Sir Timothy a limited annual allowance (which she had to repay when Percy Florence inherited the estate), but to the end of his days he refused to meet her in person and dealt with her only through lawyers. Mary Shelley busied herself with editing her husband's poems, among other literary endeavors, but concern for her son restricted her options. Sir Timothy threatened to stop the allowance if any biography of the poet were published. In 1826, Percy Florence became the legal heir of the Shelley estate after the death of Charles Shelley, his father's son by Harriet Shelley. Sir Timothy raised Mary's allowance from £100 a year to £250 but remained as difficult as ever. Mary Shelley enjoyed the stimulating society of William Godwin's circle, but poverty prevented her from socialising as she wished. She also felt ostracised by those who, like Sir Timothy, still disapproved of her relationship with Percy Bysshe Shelley.

In the summer of 1824, Mary Shelley moved to Kentish Town in north London to be near Jane Williams. She may have been, in the words of her biographer Muriel Spark, "a little in love" with Jane. Jane later disillusioned her by gossiping that Percy had preferred her to Mary, owing to Mary's inadequacy as a wife. At around this time, Mary Shelley was working on her novel, The Last Man (1826); and she assisted a series of friends who were writing memoirs of Byron and Percy Shelley — the beginnings of her attempts to immortalise her husband. She also met the American actor John Howard Payne and the American writer Washington Irving, who intrigued her. Payne fell in love with her and in 1826 asked her to marry him. She refused, saying that after being married to one genius, she could only marry another. Payne accepted the rejection and tried without success to talk his friend Irving into proposing himself. Mary Shelley was aware of Payne's plan, but how seriously she took it is unclear.

In 1827, Mary Shelley was party to a scheme that enabled her friend Isabel Robinson and Isabel's lover, Mary Diana Dods, who wrote under the name David Lyndsay, to embark on a life together in France as man and wife. With the help of Payne, whom she kept in the dark about the details, Mary Shelley obtained false passports for the couple. In 1828, she fell ill with smallpox while visiting them in Paris. Weeks later she recovered, unscarred but without her youthful beauty.

During the period 1827–40, Mary Shelley was busy as an editor and writer. She wrote the novels Perkin Warbeck (1830), Lodore (1835), and Falkner (1837). She contributed five volumes of Lives of Italian, Spanish, Portuguese, and French authors to Lardner's Cabinet Cyclopaedia. She also wrote stories for ladies' magazines. She was still helping to support her father, and they looked out for publishers for each other. In 1830, she sold the copyright for a new edition of Frankenstein for £60 to Henry Colburn and Richard Bentley for their new Standard Novels series. After her father's death in 1836 at the age of eighty, she began assembling his letters and a memoir for publication, as he had requested in his will; but after two years of work, she abandoned the project. Throughout this period, she also championed Percy Shelley's poetry, promoting its publication and quoting it in her writing. By 1837, Percy's works were well-known and increasingly admired. In the summer of 1838 Edward Moxon, the publisher of Tennyson and the son-in-law of Charles Lamb, proposed publishing a collected works of Percy Shelley. Mary was paid £500 to edit the Poetical Works (1838), which Sir Timothy insisted should not include a biography. Mary found a way to tell the story of Percy's life, nonetheless: she included extensive biographical notes about the poems.

Mary Shelley continued to treat potential romantic partners with caution. In 1828, she met and flirted with the French writer Prosper Mérimée, but her one surviving letter to him appears to be a deflection of his declaration of love. She was delighted when her old friend from Italy, Edward Trelawny, returned to England, and they joked about marriage in their letters. Their friendship had altered, however, following her refusal to cooperate with his proposed biography of Percy Shelley; and he later reacted angrily to her omission of the atheistic section of Queen Mab from Percy Shelley's poems. Oblique references in her journals, from the early 1830s until the early 1840s, suggest that Mary Shelley had feelings for the radical politician Aubrey Beauclerk, who may have disappointed her by twice marrying others.

Mary Shelley's first concern during these years was the welfare of Percy Florence. She honoured her late husband's wish that his son attend public school, and, with Sir Timothy's grudging help, had him educated at Harrow. To avoid boarding fees, she moved to Harrow on the Hill herself so that Percy could attend as a day scholar. Though Percy went on to Trinity College, Cambridge, and dabbled in politics and the law, he showed no sign of his parents' gifts. He was devoted to his mother, and after he left university in 1841, he came to live with her.

In 1840 and 1842, mother and son travelled together on the continent, journeys that Mary Shelley recorded in Rambles in Germany and Italy in 1840, 1842 and 1843 (1844). In 1844, Sir Timothy Shelley finally died at the age of ninety, "falling from the stalk like an overblown flower", as Mary put it. For the first time, she and her son were financially independent, though the estate proved less valuable than they had hoped.

In the mid-1840s, Mary Shelley found herself the target of three separate blackmailers. In 1845, an Italian political exile called Gatteschi, whom she had met in Paris, threatened to publish letters she had sent him. A friend of her son's bribed a police chief into seizing Gatteschi's papers, including the letters, which were then destroyed.Shortly afterwards, Mary Shelley bought some letters written by herself and Percy Bysshe Shelley from a man calling himself G. Byron and posing as the illegitimate son of the late  Lord Byron. Also in 1845, Percy Bysshe Shelley's cousin Thomas Medwin approached her claiming to have written a damaging biography of Percy Shelley. He said he would suppress it in return for £250, but Mary Shelley refused.

In 1848, Percy Florence married Jane Gibson St John. The marriage proved a happy one, and Mary Shelley and Jane were fond of each other. Mary lived with her son and daughter-in-law at Field Place, Sussex, the Shelleys' ancestral home, and at Chester Square, London, and accompanied them on travels abroad.

Mary Shelley's last years were blighted by illness. From 1839, she suffered from headaches and bouts of paralysis in parts of her body, which sometimes prevented her from reading and writing. On 1 February 1851, at Chester Square, she died at the age of fifty-three from what her physician suspected was a brain tumour. According to Jane Shelley, Mary Shelley had asked to be buried with her mother and father; but Percy and Jane, judging the graveyard at St Pancras to be "dreadful", chose to bury her instead at St Peter's Church, Bournemouth, near their new home at Boscombe. On the first anniversary of Mary Shelley's death, the Shelleys opened her box-desk. Inside they found locks of her dead children's hair, a notebook she had shared with Percy Bysshe Shelley, and a copy of his poem Adonaïs with one page folded round a silk parcel containing some of his ashes and the remains of his heart.