Omar ibn Abd al-Aziz was an Umayyad caliph who ruled from 717 to 720 CE. He is often remembered for his efforts to reform the Islamic state and promote justice. His reign is considered a period of relative peace and prosperity, and he is known for his commitment to the welfare of his subjects. He implemented policies that aimed to reduce corruption and improve the administration of the Islamic Empire. Omar ibn Abd al-Aziz also encouraged the compilation of Hadith and the study of Islamic law, which contributed to the development of Islamic scholarship during his time.