Umar ibn al-Khattab

Umar ibn al-Khattab was born in Mecca into the Banu Adi clan of the Quraysh tribe during the late 6th century CE. Initially an opponent of Islam, he converted in 616 CE and became one of Muhammad's closest companions, participating in many battles and serving as a chief adviser to the first caliph, Abu Bakr. After Abu Bakr's death, Umar became the second Rashidun caliph, overseeing rapid expansion of the Islamic state, including the conquest of the Sasanian Empire and much of the Byzantine territories. He is credited with introducing the Hijri calendar and is revered in Sunni tradition as a just and powerful ruler. Umar was assassinated in 644 CE by a Persian slave. His leadership significantly shaped the early Muslim community and the Islamic empire.