hegira

In the year A.D. 622, the prophet Muhammad was forced to flee his native city, Mecca, to escape persecution from those who rejected his message. Muhammad, the founder of Islam, migrated with a number of his followers to Medina, where they were guaranteed protection by local clans. This event, which traditionally marks the beginning of the Islamic era, is known in Arabic as the Hijra-literally, "departure." That Arabic term passed into Medieval Latin (where it was modified to Hegira) and from there it eventually made its way into English. By the mid-18th century, English speakers were using hegira for other journeys, too-especially arduous ones.