Umar was part of the first emigration (Hijra) to Yathrib (renamed Medinat al Nabi, or simply Medina shortly thereafter) in 622 C.E. He wa present at Badr, Uhud, Khaybar, and the raid on Syria, as well as many other engagements.
Umar was given the key to the city by the Greek Orthodox patriarch, Sophronius, and invited to pray at the Church of the Holy Sepulchre.
Umar's killer (Abu-Lu'lu'ah) was a Persian slave who was angered with Umar; he stabbed the Caliph six times as Umar led prayers in the Masjid al Nabawi mosque in Medina.
Umar was born in Mecca around 581 to the Adi clan of the Quraish tribe.
Umar belonged to a family of average class, but he was able to become literate and was well known for his physical strength, becoming a champion wrestler.
Umar was initially angered by this and began threatening them, but their resolve and fearlessness led Umar to a change of heart.