most medieval European societies, while duly noting that the protection was limited because of regulation by and obligations to government such as taxation (compare jizya and zakat) and military service differed between religions. In modern concepts of religious freedom, the law is usually blind to religious affiliation in conferring such matters. In Antiquity, a syncretic point of view often allowed communities of traders to operate under their own customs. When street mobs of separate quarters clashed in a Hellenistic or Roman city, the issue was generally perceived to be an infringement of community rights. Cyrus the Great established the Achaemenid Empire ca. 550 BC, and initiated a general policy of permitting religious freedom throughout the empire, documenting this on the Cyrus Cylinder. Some of the historical exceptions have been in regions where one of the revealed religions has been in a position of power: Judaism, Zoroastrianism, Christianity and Islam. Others have been where the established order has felt threatened, as shown in the trial of Socrates in 399 BC. Freedom of religious worship was established in the Buddhist Maurya Empire of ancient India by Ashoka the Great in the 3rd century BC, which was encapsulated in the Edicts of Ashoka. GreekJewish clashes at Cyrene in 73 AD and 117 AD and in Alexandria in 115 AD provide examples of cosmopolitan cities as scenes of tumult. Genghis Khan was one of the first rulers who in 13th century enacted a law explicitly guaranteeing religious freedom to everyone and every religion. Ancient Roman policy The Romans tolerated most religions, including Judaism, and encouraged local subjects to continue worshipping their own gods. They did not however, tolerate Christianity until it was legalised by the Roman emperor Galerius in 311. Holmes and Bickers note that as long as Christianity was treated as a part of Judaism it enjoyed the same freedom, but the Christian claim to religious exclusivity meant its followers found themselves subject to hostility. The early Christian apologist Tertullian was the first-known writer referring to the term libertas religionis. The Edict of Milan guaranteed freedom of religion in the Roman Empire until the Edict of Thessalonica in 380, which outlawed all religions except Christianity. Muslim world Following a period of fighting lasting around a hundred years before 620 AD which mainly involved Arab and Jewish inhabitants of Medina (then known as Yathrib), religious freedom for Muslims, Jews and pagans was declared by