Namesakes

Islamic Caliphs: 2 caliphs
Caliph Umar ibn Al-Khattab   634-644   Rashidun  
Caliph Umar II ibn Abd al-Aziz   717-720   Umayyad  
Notable Philosophers and Thinkers: 1 mathematician
Omar Khayyám (a.k.a. Umar)   1048-1131  
Notable Writers: 1 poet
Omar Khayyám (a.k.a. Umar)   1048-1131