“Treaty” means an international agreement concluded in writing between states and subject to international law, whether covered by a single act or in two or more interconnected instruments, whatever its particular name. The origins of international law date back to antiquity. Early examples include the peace agreements between the Mesopotamian city-states of Lagash and Umma (about 2100 BC) and an agreement between the Egyptian pharaoh Ramses II and the Egyptian king Hattouilis III, concluded in 1258 BC. Intergovernmental pacts and agreements of various kinds have also been negotiated and concluded by communities around the world, from the Eastern Mediterranean to East Asia. The concept of sovereignty was spread throughout the world by European powers that had established colonies and spheres of influence over virtually every society. Positivism reached its peak in the late nineteenth century and its influence began to weaken after the unprecedented bloodshed of the First World War, which spurred the creation of international organizations such as the Federation of Nations, founded in 1919 to ensure peace and security. International law has begun to incorporate more naturalistic concepts such as self-determination and human rights. The Second World War accelerated this development and led to the creation of the United Nations, whose Charter established principles such as non-aggression, non-interference and collective security. This resulted in a more robust international legal order, supported by institutions such as the International Court of Justice and the United Nations Security Council, as well as multilateral agreements such as the Genocide Convention. The International Law Commission (ILC) was established in 1947 to assist in the development, codification and strengthening of international law The Dutch jurist Hugo Grotius (1583-1645) is widely regarded as the most visible figure in international law and is one of the first scholars to articulate an international order consisting of a “society of states” that is not the result of violence or war, but is governed by real laws.
mutual agreements and customs.  Grotius secularized international law and organized it into a global system; His work De Jure Belli ac Pacis (On the Law of War and Peace) of 1625 established a system of principles of natural law that bound all nations regardless of stakes or local laws. He also highlighted the freedom of the high seas, not only relevant to the growing number of European states exploring and colonizing the world, but which remains today a cornerstone of international law. Although the modern study of international law did not begin until the early nineteenth century, the sixteenth-century scholars Gentili, Vitoria and Grotius laid the foundation and are widely regarded as the “fathers of international law.”  International law defines the framework and criteria for identifying states as the main actors in the international legal system. The existence of State control and jurisdiction over the territory, international law deals with the acquisition of territory, State immunity and the legal responsibility of States in their conduct among themselves. Similarly, international law concerns the treatment of individuals within national borders. There is therefore a comprehensive regime that deals with group rights, the treatment of foreigners, refugee rights, international crimes, nationality issues and human rights in general. It also covers the important functions of the maintenance of international peace and security, arms control, the peaceful settlement of disputes and the settlement of the use of force in international relations. Although the law is not capable of stopping the outbreak of war, it has developed principles to regulate the conduct of hostilities and the treatment of prisoners. International law is also used to address issues relating to the global environment, global commons such as international waters and space, global communications and global trade.
. . .