A peace congress, in international relations, has at times been defined in a way that would distinguish it from a peace conference (usually defined as a diplomatic meeting to decide on a peace treaty), as an ambitious forum to carry out dispute resolution in international affairs, and prevent wars. This idea was widely promoted during the nineteenth century, anticipating the international bodies that would be set up in the twentieth century with comparable aims.
The genesis of the idea of a meeting of representatives of different nations to obtain by peaceful arbitrament a settlement of differences has been traced to the year 1623 in modern history, to a French monk, Émeric Crucé, who wrote a work entitled "The New Cyneas", a discourse showing the opportunities and the means for establishing a general peace and liberty of conscience to all the world and addressed to the monarch and the sovereign princes of the time. He proposed that a city, preferably Venice, should be selected where all the powers had ambassadors and that there should be a universal union, including all peoples. He suggested careful arrangement as to priority, giving the first place to the pope.
Two years after this publication, in 1625, appeared in Latin the work of Hugo Grotius "On the Right of War and Peace", pleading for a mitigation of some of the barbarous usages of war.
William Penn had a plan for the establishment of a "European Dyet, Parliament or Estates". He was followed by other writers of different nationalities.
The concept of a peaceful community of nations had also been outlined in 1795, when Immanuel Kant’s Perpetual Peace: A Philosophical Sketch outlined the idea of a league of nations that would control conflict and promote peace between states.
International co-operation to promote collective security originated in the Concert of Europe that developed after the Napoleonic War in the nineteenth 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 about humanitarian relief during war and the international Hague Conventions of 1899 and 1907 governing rules of war and the peaceful settlement of international disputes.