The concept of a peaceful community of nations had been proposed as far back as 1795, when
Perpetual Peace: A Philosophical Sketch
 outlined the idea of a league of nations to control conflict and promote peace between states. Kant argued for the establishment of a peaceful world community, not in a sense of a global government, but in the hope that each state would declare itself a free state that respects its citizens and welcomes foreign visitors as fellow rational beings, thus promoting peaceful society worldwide.
 International co-operation to promote collective security originated in the
Concert of Europe that developed after the
Napoleonic Wars in the 19th century in an attempt to maintain the status quo between European states and so avoid war. This period also saw the development of international law, with the first
Geneva Conventions establishing laws dealing with humanitarian relief during wartime, and the international
Hague Conventions of 1899 and 1907 governing rules of war and the peaceful settlement of international disputes.
 As historians William H. Harbaugh and
Ronald E. Powaski point out,
Theodore Roosevelt was the first American President to call for an international league.
 At the acceptance for his Nobel Prize, Roosevelt said: "it would be a masterstroke if those great powers honestly bent on peace would form a League of Peace"
The forerunner of the League of Nations, the
Inter-Parliamentary Union (IPU), was formed by the peace activists
William Randal Cremer and
Frédéric Passy in 1889 (and is currently still in existence as an international body with a focus on the various elected legislative bodies of the world.) The IPU was founded with an international scope, with a third of the members of
parliaments (in the 24 countries that had parliaments) serving as members of the IPU by 1914. Its foundational aims were to encourage governments to solve international disputes by peaceful means. Annual conferences were established to help governments refine the process of international arbitration. Its structure was designed as a council headed by a president, which would later be reflected in the structure of the League.
, one of the earliest advocates for a League of Nations.
At the start of the First World War the first schemes for international organisation to prevent future wars began to gain considerable public support, particularly in Great Britain and the United States.
Goldsworthy Lowes Dickinson, a British political scientist, coined the term "League of Nations" in 1914 and drafted a scheme for its organisation. Together with
Lord Bryce, he played a leading role in the founding of the group of internationalist pacifists known as the Bryce Group, later the
League of Nations Union.
 The group became steadily more influential among the public and as a pressure group within the then governing
Liberal Party. In Dickinson's 1915 pamphlet After the War he wrote of his "League of Peace" as being essentially an organisation for arbitration and conciliation. He felt that the secret diplomacy of the early twentieth century had brought about war and thus could write that, "the impossibility of war, I believe, would be increased in proportion as the issues of foreign policy should be known to and controlled by public opinion." The ‘Proposals’ of the Bryce Group were circulated widely, both in England and the US, where they had a profound influence on the nascent international movement.
Within two weeks of the start of the war, feminists began to mobilise against the war.
 Having been barred from participating in prior peace organizations,
 American women formed a Women's Peace Parade Committee to plan a silent protest to the war. Led by chairwoman
Fanny Garrison Villard, women from trade unions, feminist organizations, and social reform organizations, such as
Kate Waller Barrett,
Mary Ritter Beard,
Carrie Chapman Catt,
Lillian Wald, and others, organized 1500 women, who marched down
Fifth Avenue on August 29, 1914.
 As a result of the parade,
Jane Addams became interested in proposals by two European suffragists—Hungarian
Rosika Schwimmer and British
Emmeline Pethick-Lawrence—to hold a peace conference.
 On 9-10 January 1915, a peace conference directed by Addams was held in
Washington, D. C., where the delegates adopted a platform calling for creation of international bodies with administrative and legislative powers to develop a "permanent league of neutral nations" to work for peace and disarmament.
Within months a call was made for an international women's conference to be held in
The Hague. Coordinated by
Aletta Jacobs and
Rosa Manus, the Congress, which opened on April 28, 1915 was attended by 1,136 participants from both neutral and
 and resulted in the establishment of an organization which would become the
Women's International League for Peace and Freedom (WILPF). At the close of the conference, two delegations of women were dispatched to meet with European heads of state over the next several months. They secured agreement from reluctant Foreign Ministers, who overall felt that such a body would be ineffective, but agreed to participate or not impede creation of a neutral mediating body, if other nations agreed and if President
Woodrow Wilson would initiate a body. In the midst of the War, Wilson refused.
In 1915, a similar body to the Bryce group proposals was set up in the United States by a group of like-minded individuals, including
William Howard Taft. It was called the
League to Enforce Peace and was substantially based on the proposals of the Bryce Group.
 It advocated the use of arbitration in conflict resolution and the imposition of sanctions on aggressive countries. None of these early organisations envisioned a continuously functioning body; with the exception of the
Fabian Society in England, they maintained a legalistic approach that would limit the international body to a court of justice. The Fabians were the first to argue for a "Council" of states, necessarily the
Great Powers, who would adjudicate world affairs, and for the creation of a permanent secretariat to enhance international co-operation across a range of activities.
In the course of the
diplomatic efforts surrounding World War I, both sides had to clarify their long-term war aims. By 1916 in Britain, the leader of the
Allies, and in neutral United States, long-range thinkers had begun to design a unified international organisation to prevent future wars. Historian Peter Yearwood argues that when the new coalition government of
David Lloyd George took power in December 1916, there was widespread discussion among intellectuals and diplomats of the desirability of establishing such an organisation, when Lloyd George was challenged by Wilson to state his position Regarding the postwar, he endorsed such an organisation. Wilson himself Included in his
Fourteen Points in January 1918 a "league of nations to insure peace and justice." British foreign secretary,
Lord Balfour, argued that, as a condition of durable peace, "behind international law, and behind all treaty arrangements for preventing or limiting hostilities, some form of international sanction should be devised which would give pause to the hardiest aggressor."
By the time Germany gave up in November 1918, the war had had a profound impact, affecting the social, political and economic systems of Europe and inflicting psychological and physical damage.
 Anti-war sentiment rose across the world; the First World War was described as "
the war to end all wars", and its possible causes were vigorously investigated. The causes identified included arms races, alliances, militaristic nationalism, secret diplomacy, and the freedom of sovereign states to enter into war for their own benefit. One proposed remedy was the creation of an international organisation whose aim was to prevent future war through disarmament, open diplomacy, international co-operation, restrictions on the right to wage war, and penalties that made war unattractive.
In London Balfour commissioned the first official report into the matter in early 1918, under the initiative of Lord
Robert Cecil. The British committee was finally appointed in February 1918. It was led by
Walter Phillimore (and became known as the Phillimore Committee), but also included
William Tyrrell, and
 The recommendations of the so-called
Phillimore Commission included the establishment of a "Conference of Allied States" that would arbitrate disputes and impose sanctions on offending states. The proposals were approved by the British government, and much of the commission's results were later incorporated into the
Covenant of the League of Nations.
The French also drafted a much more far-reaching proposal in June 1918; they advocated annual meetings of a council to settle all disputes, as well as an "international army" to enforce its decisions.
The American President Woodrow Wilson instructed
Edward M. House to draft a US plan which reflected Wilson's own idealistic views (first articulated in the
Fourteen Points of January 1918), as well as the work of the Phillimore Commission. The outcome of House's work, and Wilson's own first draft, proposed the termination of "unethical" state behaviour, including forms of espionage and dishonesty. Methods of compulsion against recalcitrant states would include severe measures, such as "blockading and closing the frontiers of that power to commerce or intercourse with any part of the world and to use any force that may be necessary..."
The two principal drafters and architects of the
covenant of the League of Nations
 were Lord
Robert Cecil (a British diplomat), and
Jan Smuts (a South African statesman). Smuts' proposals included the creation of a Council of the great powers as permanent members and a non-permanent selection of the minor states. He also proposed the creation of a
Mandate system for captured colonies of the
Central Powers during the war. Cecil focused on the administrative side, and proposed annual Council meetings and quadrennial meetings for the Assembly of all members. He also argued for a large and permanent secretariat to carry out the League's administrative duties.
The official opening of the League of Nations, 15 November 1920
Paris Peace Conference in 1919, Wilson, Cecil, and Smuts all put forward their draft proposals. After lengthy negotiations between the delegates, the
Miller draft was finally produced as a basis for the
 After more negotiation and compromise, the delegates finally approved of the proposal to create the League of Nations (
French: Société des Nations,
German: Völkerbund) on 25 January 1919. The final
Covenant of the League of Nations was drafted by a special commission, and the League was established by Part I of the
Treaty of Versailles. On 28 June 1919, 44 states signed the Covenant, including 31 states which had taken part in the war on the side of the
Triple Entente or joined it during the conflict.
French women's rights advocates invited international feminists to participate in a parallel conference to the Paris Conference in hopes that they could gain permission to participate in the official conference.
 The Inter-Allied Women's Conference asked to be allowed to submit suggestions to the peace negotiations and commissions and were granted the right to sit on commissions dealing specifically with women and children.
 Though they asked for enfranchisement and full legal protection under the law equal with men,
 those rights were ignored. Women won the right to serve in all capacities, including as staff or delegates in the League of Nations organization. They also won a declaration that member nations should prevent
trafficking of women and children and should equally support humane conditions for children, women and men labourers. At the
Zürich Peace Conference held between 17-19 May, 1919, the women of the WILPF condemned the terms of the
Treaty of Versailles for both is punitive measures, as well as its failure to provide for condemnation of violence and exclusion of women from civil and political participation. Upon reading the Rules of Procedure for the League of Nations,
Catherine Marshall, an English suffragist, discovered that the guidelines were completely undemocratic and they were modified based on her suggestion.
The League would be made up of a General Assembly (representing all member states), an Executive Council (with membership limited to major powers), and a permanent secretariat. Member states were expected to "respect and preserve as against external aggression" the territorial integrity of other members and to
disarm "to the lowest point consistent with domestic safety." All states were required to submit complaints for
judicial inquiry before going to war.
 The Executive Council would create a
Permanent Court of International Justice to make judgements on the disputes.
Despite Wilson's efforts to establish and promote the League, for which he was awarded the
Nobel Peace Prize in October 1919, the United States never joined. Senate Republicans led by
Henry Cabot Lodge wanted a League with the reservation that only Congress could take the U.S. into war. Lodge gained a majority of Senators. Wilson refused to allow a compromise and the needed 2/3 majority was lacking.
The League held its first council meeting in Paris on 16 January 1920, six days after the Versailles Treaty and the Covenant of the League of Nations came into force. On 1 November 1920, the headquarters of the League was moved from London to Geneva, where the first General Assembly was held on 15 November 1920.
Palais Wilson on Geneva's western lakeshore, named after US President Woodrow Wilson in recognition of his efforts towards the establishment of the League, was the League's first permanent home.