According to Jewish tradition, Umar set aside the Christian ban on Jews and allowed them into Jerusalem and to worship. Umar was assassinated by the Persian slave Abu Lu'lu'a Firuz in 644.

Who was the second Khalifa?

Umar ibn al-Khattab (r. 634-644 CE) was the second caliph of the Rashidun Caliphate (632-661 CE, as the first four caliphs are referred to by the Sunni Muslims).

Who killed Caliph Umar?

Umar was assassinated by the Persian slave Abu Lu'lu'a Firuz in 644. Umar is revered in the Sunni tradition as a great ruler and paragon of Islamic virtues, and some hadiths identify him as the second greatest of the Sahabah after Abu Bakr. He is viewed negatively in the Twelver Shia tradition.