(hiǧra). Emigration, movement of the prophet Muḥammad and some of his followers from Mecca to Medina in AD 622 after tribal difficulties (withdrawal of the clan protection on the part of his tribe Quraiš); beginning of the Islamic calendar. Only with the hejira did Mohammed's work as a statesman begin; it also marked the starting-point of the actual spread of Islam (initially through a policy of alliances).
A. Noth, Die Hiǧra, in: U. Haarmann (ed.), Geschichte der arabischen Welt, 1987, 11-57.