Muhammad was born in Mecca in 570 AD and worked as a merchant. At age 40, he began receiving revelations from God that became the basis of Islam's holy book, the Quran. By 630, he had unified most of Arabia under the religion of Islam. He encountered opposition from Mecca's leaders when his message condemned their idol worship and polytheism. This forced him to emigrate to Medina in 622, marking the beginning of the Muslim calendar. From there, he gradually gained more followers and military strength. By 630, he conquered Mecca with minimal casualties and destroyed the city's pagan idols. Muhammad died in Medina in 632 at age 62 and was buried at a mosque