Umar ibn Abd al-Aziz (Arabic: عمر بن عبد العزيز, romanized: ʿUmar ibn ʿAbd al-ʿAzīz; 2 November 682 – c. 5 February 720), commonly known as Umar II, was the eighth Umayyad caliph, ruling from 22 September 717 until his death in 720. He was also a cousin of the former caliph, being the son of Abd al-Malik's younger brother, Abd al-Aziz. He was also a matrilineal great-grandson of the second caliph, Umar ibn Al-Khattab. He has been described as "the most pious and devout" of the Umayyad rulers.