By the 4th century (300-400) AD, Himyar conquered all other kingdoms of South Arabia. Christianity came to Arabia, from Abyssinia and Syria. Some people in Himyar followed Judaism. A Jewish king of Himyar killed many Christians. Abyssinia and Rome ruled by Justinian were both Christian countries. In 525 they attacked Himyar. In North and Central Arabia, two kingdoms had appeared in the 3rd and 4th centuries AD: The Lakhmids and the Ghassanids. The Sassanid Empire from Persia supported the Lakhmids (and Himyar), and Rome supported the Ghassanids. These two empires were at war. In the 6th century the Bedouins fought each other in wars called the Jahiliyyah. 