Joseph Luns was born in a Roman Catholic, francophile and artistic family. His mother’s family originated from Alsace - Lorraine and had moved to Belgium after the annexation of the region by the German Reich in 1871. His father Huib Luns was a versatile artist and a gifted educationalist, who ended his career as professor of architectural drawing at the Technical University of Delft. Luns got his secondary education in Amsterdam and Brussels. He opted to become a commissioned officer of the Dutch Royal Navy, but registered too late to be selected. Therefore, Luns decided to study law at Amsterdam University during the period 1932 - 1937. Like his father, Luns demonstrated a preference for conservative and authoritarian political parties and an interest in international politics. As a young student he positioned himself on the political right, favoring a strong authority for the state and being of the opinion that socialism, due to its idealistic ideology, had fostered the rising of fascism and nazism. Luns himself had been a silent member of the National Socialist Movement in the Netherlands (NSB), but left in 1936 before this party chose a strongly anti - semitic course.

His choice for a diplomatic career was inspired by his father. He joined the Dutch Diplomatic Service in 1938 and after a two year assignment at the Private Office of the Foreign Minister he was appointed as attaché in Bern (Switzerland) in 1940 and in late 1941 he moved to Lisbon (Portugal). In both countries he was involved in assistance to Dutch refugees, political espionage and counterintelligence. In 1943 he was transferred to the Dutch embassy in London. Ambassador E. Michiels van Verduynen discovered Luns' great affinity for the political element in international affairs and entrusted him with important files on Germany which Luns handled with great skill.

In 1949 Luns was appointed as deputy Dutch permanent representative to the United Nations. He worked closely with his new chief D. Von Balluseck, a political appointee without diplomatic experience. After the Netherlands became a member of the Security Council he temporarily chaired the Disarmament Commission. Luns was sceptical of the importance of the United Nations for international peace, believing it at times to be more like a forum for propaganda than a center for solving international conflicts. Still, he was of opinion that it was worthwhile to keep the UN in shape because it was the sole international organisation which offered opportunities for discussions between all states.

Due to the tenacity of the Dutch Catholic People's Party to occupy the Foreign Ministry after the 1952 elections, Luns entered Dutch politics as the favorite of its political leader Romme. His co-Minister was J.W. Beyen, an international banker, not affiliated to any political party, but protégé of Queen Juliana. The two ministers had a completely different style of operating and clashed even before the end of 1952. However, they accommodated and avoided future conflicts by a very strict division of labour. Luns was responsible for bilateral relations, Benelux and international organisations. After the 1956 elections Beyen left office and Luns stayed as Foreign Minister until 1971 in both center - left and center - right governments. Bilateral relations with Indonesia and the German Federal Republic, security policy and European integration were the most important issues during his tenure.

Atlantic cooperation was a fundamental aspect of Luns’ foreign policy, and Dutch foreign policy in general. In the opinion of Luns, Western Europe could not survive the Cold War without American nucleair security and he therefore promoted strong and intensified political and military cooperation in NATO. Luns accepted American leadership of the Atlantic Alliance as such but expected better cooperation between the United States and its allies, since, in Luns’ opinion, the former too often acted independently of its allies, particularly in decolonisation issues. Although a great supporter of Atlantic cooperation, Luns could also be critical of U.S. foreign policy and in bilateral relations he defended Dutch national interests strongly, as well as expecting American support in the bilateral difficulties with Indonesia.

In 1952 Luns expected to improve relations with Indonesia without transferring the disputed area of West New Guinea to the former colony. By 1956 however, this policy had proved ineffectual, while Luns and the Dutch government were still determined not to transfer West New Guinea to the Republic of Indonesia. When in 1960 it became obvious that allied support for this policy, particularly from the United States, was waning, Luns tried to find an intermediate solution by transferring the administration of the territory to the United Nations, yet this attempt to keep West New Guinea out of Indonesian hands failed as well. After difficult negotiations the area was finally transferred to the Republic of Indonesia in 1963 after a short interim administration of the UN. Despite his personal anger over this outcome, which was considered a personal defeat by Luns, the foreign minister nevertheless worked to restore relations with Indonesia in the aftermath of the West New Guinea problem. A visit by Indonesian president Sukarno to the Netherlands was however prevented; Luns regarded Sukarno as an unreliable dictator.

Luns was more successful in the normalisation of the bilateral relations with the Federal Republic of Germany. Luns shared Dutch public opinion in demanding that Germany recognize the damage it had caused during the Second World War, furthermore a mea culpa required. He demanded that, before any negotiations on other bilateral disputes could start, the amount of damages to be paid to Dutch war victims would be agreed upon. During the final stages of the negatotiations on bilateral disputes between the two countries, Luns decided to come to an arrangement with his German colleague on his own accord. He made concessions and because of this the Dutch parliament threatened not to ratify the agreement. With the full support of the government however, Luns was able to overcome the crisis.

European integration was permanently on Luns’ political agenda. Beyen had introduced the concept of the European Economic Community. In March 1957 Luns signed the Treaties of Rome establishing the EEC and Euratom. Although he preferred integration of a wider group of European states he accepted the group of Six of the EEC and defended the supranational structure it was based on. The endeavours of French president Charles de Gaulle to subordinate the institutions of the Six to a intergovernmental political structure, could count on strong opposition from Luns: such plans would, in his view, only serve French ambitions of a Europe independent of the United States.

Initially Luns stood alone and he was afraid that French - German cooperation would result in anti - Atlantic and anti - American policies which harmed the interests of the West. He made British membership of the European institutions conditional for his political cooperation. Gradually his views on Gaullist foreign policies were shared by the other EEC members and they joined Luns in his objections. Two of De Gaulle’s decisions stiffened the opposition: first, his denial of EEC membership to the United Kingdom in January 1963; secondly, France’s retreat from the integrated military structure of NATO in 1966. Luns played a vital role in the negotiations unwinding French participation and continuing its political membership of the Alliance. By that time Luns had internationally established his reputation as an able and reliable negotiator and was seen as an important asset in London and Washington. After the retreat of De Gaulle in 1968, the EEC Summit of The Hague in December 1969 ended the long crisis of the EEC integration process, opened the way to British membership and agreed on new venues for political cooperation, a common market and monetary union.

Throughout his years as Dutch foreign minister, Luns had gained an international status uncommon for a foreign minister of a small country. He owed this to his personal style in which duress, a high level of information, political leniency and diplomatic skills were combined with wit, galant conversation and the understanding that diplomacy was a permanent process of negotiations in which a victory should never be celebrated too exuberantly at the cost of the loser.

In 1971, Luns was appointed as NATO Secretary - General. At the time of his appointment, public protests against American policies in Vietnam were vehement throughout Western Europe and among European politicians the credibility of the American nuclear protection was in doubt. Though there were initial doubts about Luns’ skills for the job he soon proved that he was capable of managing the alliance in crisis. He regarded himself as the spokesman of the alliance and he aimed at balancing the security and political interests of the alliance as a whole.

Luns was in favor of negotitiating with the Soviet Union and the Warsaw Pact members on the reduction of armaments, on the condition that the Western defense was kept in shape during such negotiations. European members of NATO, according to Luns, should understand that the United States carried international responsibilities while the latter should understand that in-depth consultation with the European governments was conditional to forging a united front on the international stage, which could be accepted and endorsed by all members of NATO. U.S. - Soviet negotiations on mutual troop reductions and the strategic nuclear arsenal caused severe tensions. Luns convinced American leaders that it undermined the credibility in Western Europe of their nuclear strategy by neglecting European fears of a change of strategy which would leave Europe unprotected in case of a Soviet nuclear attack. The modernization of the tactical nuclear forces by the introduction of the neutron bomb and cruise missiles caused deep divisions. In the end Luns succeeded in keeping NATO together in the so called Double - Track Decision of December 1979. The deployment of these new weapon systems was linked to success in American - Soviet arms reduction talks.

It was also the duty of the Secretary-General to mediate in cause of conflicts within the alliance. He was successful in the conflict between Great Britain and Iceland, the so-called Second Cod War, not by pressuring the Icelandic government to end its aggressive behaviour against British trawlers, but by convincing the British government that it had to take the first step by calling back its destroyers in order to open the way to negotiations. Luns failed however in the conflict between Greece and Turkey over the territorial boundaries and Cyprus. Due to lack of cooperation on both sides Luns was unable to mediate or advice on procedures to find a way out.

Luns retired as Secretary - General in 1984, staying in office for a full 13 years. Because of the changes the 1960s and 1970s had brought to Dutch society and culture, the strongly conservative Luns decided not to return to his home country but settled in Brussels to spend his remaining years in retirement. Joseph Luns died on July 17, 2002, aged 90.

• Luns remained a practicing Catholic throughout his life and was generally sympathetic to the traditionalist Catholic position, although he never affiliated himself with dissident groups. Luns did visit the Tridentine Mass held by the assumptionist priest Winand Kotte, who opposed the modernising policies of the Second Vatican Council, in the Saint Wilibrord Church of Utrecht in August 1971. This seems to have been something of a misunderstanding on Luns' part however, who had never heard of Kotte's anti - Second Council movement and did not wish to be affiliated with it.
• Luns was awarded many high - ranking awards during his lifetime, among them the Grand Cross of the Légion d’Honneur in 1954, Member of Order of Companions of Honour of the British Queen in 1971 and the Presidential Medal of Freedom by then President Ronald Reagan in 1984.
• His favourite reading material included classical literature, history books (Luns was an expert on the history of the Napoleonic era) and detective novels, while due to his interests in international navies, the latest edition of Jane’s Fighting Ships was always within reach in his office.
• Luns was an avid stamp collector.
• Luns' spouse Baroness Lia van Heemstra was a niece of baroness Ella van Heemstra, the mother of actress Audrey Hepburn.