Umar Ibn Al-Khattab (RA) was the most influential and undoubtedly the second and greatest Muslim caliph who was contemporary of last Prophet Hazrat Muhammad (P.B.U.H) and even was born in the city of last Prophet in Mekkah. However the correct year of his birth is unknown but it has guessed that he was born in 586 AD.
Umar Ibn Al-Khattab was firstly emerged as harsh enemy of Prophet Muhammad (P.B.U.H) and His religion. Although after sometime, he entered Islam and became the strongest supporter as the story of adopting Christianity by St. Pak belongs to the same species. He then became a close adviser of the Prophet Muhammad (P.B.U.H) and his remaining life completed with the same title.
Prophet Muhammad (P.B.U.H) who died in 632 A.D did not appoint His successor hand due to which Umar Ibn Al-Khattab endorsed Hazrat Abbu Bakr (RA) for the succession of Prophet Muhammad (P.B.U.H) as he was close companion and father in law of last Prophet (P.B.U.H). In this way, cold war for power was ended and generally Hazrat Abu Bakr (R.A) was accepted as the Muhammad’s successor and first caliph of Muslim.
Hazrat Abu Bakr (R.A) was a successful caliph but he died after two years as he had chosen the name of Umar Ibn Al-Khattab for his succession. Therefore, Umar Ibn Al-Khattab become Caliph in 634 AD and his government lasted till 644 A.D. However, Arabs won important victories during the ten-year rule of Umar Ibn Al-Khattab including defeating the Byzantine armies in the battle of 636 A.D as well as Damascus was conquered in these years and after two years later yuslm also joined Arab. In 639 AD, Arab armies conquered Egypt which was an important part of the Byzantine Empire. Arab won the most important victory of battle Qudsia in the reign of Umar Ibn Al-Khattab (R.A) in 637 AD.
Although, all Iraq had become the part of the Arab realm in 641 AD but not only this Arab also decisively defeated the armies of Sassanid Emperor. Arab had also conquest the several parts of western Iran till the death of Umar Ibn Al-Khattab (RA) in 644 AD. Moreover, Arab had made Palestinian and Syria as their submissive until 644 A.D and were advancing towards Turkey.However, Arab armies did not have any effect on the speed of victories after the death of Umar Ibn Al-Khattab as they shortly completed victory of Iran in East while they further moved to North Africa in the West.