Introduction - International law is not just a result of few treaties of 19th and 20th centuries but its origin can be traced back to ancient times. Peace treaties between the Mesopotamian city of Lagash and Umma are considered as beginning of international law. The concept of governance and international relations were developed by the Greeks, which laid down the foundation of the international legal system. The concept 'Jus Gentium' (Law of Nation) was evolved during the reign of the Roman empire, which defined and governed the relation between foreigners and Roman citizens and the status of foreigners living in Rome. Later, development of concept of Natural Law emphasized that certain rights are inherent to all humans, which helped in widening the scope of international law.