Encyclopedia of Islam

Umar ibn al-Khattab

 

(586–644)  

(r. 634–644)  second Muslim caliph, established the 

political structure of the Islamic empire

A member of the Adi clan of the q

Uraysh

 tribe, 

Umar ibn al-Khattab was born in m

ecca

. Initially 

an opponent of Muhammad, he converted to 

i

slam

 in about 615. He went on to become one of 

Muhammad’s closest advisers, accompanying him 

to m

edina

 in 622 during the h

iJra

. He became the 

Prophet’s father-in-law when Muhammad married 

his daughter, Hafsa. After Muhammad’s death 

in 632 Umar supported a

bU

  b

akr

 (r. 632–634) 

to succeed him; he himself succeeded Abu Bakr 

shortly afterward, becoming the second of the 

four Sunni “rightly guided” caliphs, or Rashidun, 

which include U

thman

 

ibn

  a

FFan

 (r. 644–655) 

and a

li

 

ibn

 a

bi

 t

alib

 (r. 656–661). Umar was the 

first caliph to adopt the title Amir al-Muminin, or 

commander of the faithful.

Under Umar’s rule, the Islamic state expanded 

from a local principality to a major power. He 

continued the military campaigns begun by Abu 

Bakr, resulting in the conquest of s

yria

, p

alestine

, 

e

gypt

,  i

raq

, and i

ran

. Umar established guide-

lines for administering these new conquests. He 

left the conquered peoples in possession of the 

land and did not require them to serve in his army 

or attempt to convert them to Islam; in return, 

they paid tribute to the government. As governors 

and administrators, Umar appointed skillful man-

agers who were loyal to him. He also established 

garrison cities to administer the newly conquered 

territory; they included Basra, at the head of the 

Persian Gulf; Kufa, on the Euphrates River; and 

Fustat, later to become c

airo

, just below the Nile 

Delta. He instituted the empire’s judiciary, set up 

a postal system, and introduced a system of taxes 

to finance the state. Umar is also credited with 

instituting the use of the Islamic 

calendar

. In