Developments in Classical International Law in the Shadow of the Cooperation and Competition of the Great Powers

International law is considered the achievement of international historical development and Transformation. In this direction, during the Middle Ages, the modern and contemporary era, we have witnessed the growing growth of international law. It seems that the end of World War II and the formation of the United Nations can be considered a turning point in the history of developments in international law, and therefore it can be divided into classical and modern periods before and after it. The present study considers the classical period in the evolution of international law from the formation of the Treaty of Westphalia in 1648 to 1945 and intends to examine the role of the great powers of this period in the formation and development of international law. To this end, the question arises that how did the great powers of the international system play a role in the formation and expansion of international law in the classical period? The hypothesis is that the great powers in the classical period in the form of cooperation and even competition with each other, by holding periodic conferences, concluding contracts, institutionalizing and creating custom, have been effective in shaping and expanding international law. It should also not be overlooked that the great powers have always taken their interests into account in international legal developments. The present study tries to examine the role of major powers in the development of international law in this period with a descriptive-analytical method according to the above considerations.