what year is considered the beginning of islam
Islamic calendar The Islamic calendar employs the Hijri era whose epoch was retrospectively established as the Islamic New Year of AD 622. During that year, Muhammad and his followers migrated from Mecca to Yathrib (now Medina) and established the first Muslim community (ummah), an event commemorated as the Hijra. In the West, dates in this era are usually denoted AH (Latin: Anno Hegirae, "in the year of the Hijra") in parallel with the Christian (AD) and Jewish eras (AM). In Muslim countries, it is also sometimes denoted as H[1] from its Arabic form ( سَنة هِجْريّة, abbreviated هـ). In English, years prior to the Hijra are reckoned as BH ("Before the Hijra").[2]
Persian Empire Iranian dynastic history was interrupted by the Arab conquest of Persia in 651Â AD, establishing the even larger Islamic caliphate, and later by the Mongol invasion. The main religion of ancient Persia was the native Zoroastrianism, but after the seventh century, it was replaced by Islam.