Modern international law is the product of many cultural and civilizational changes and mutations. it has passed through several ancient societies such as Byzantium, although one of the earliest international treaties is the Treaty of the Pearl, a peace treaty signed by the Egyptian pharaoh Ramses II with the king of the Hittites in 1296BC. This treaty included the extradition of "political refugees" and a non-aggression agreement and was based on the beliefs of the different gods of each party. The Greek cities set rules for the treatment of prisoners of war and joined together to manage particular functions such as the management of the sanctuary at Delphi. The Romans, with Gaius, conceived of jus gentium as a law that applied to all of humanity. It is not, however, public international law as we understand it today.