A beloved relative of Prophet Muhammad, the second caliph Umar ibn al-Khattab, served greatly to regulate the institutions of the young caliphate and became a symbol of justice because of his meticulous statesmanship

The second caliph, Abu Hafs Umar ibn al-Khattab, or Umar, father of Hafs, son of al-Khattab, known for his pious and just character, was one of the most significant political and religious actors of Islam after Prophet Muhammad's death. He succeeded Abu Bakr in 634 and ruled Muslim society as a whole until Piruz Nahavandi, a former Sassanian soldier enslaved after a battle won by Muslims, assassinated him in 644 in Medina.
Early lifeUmar was born to a notable family in Mecca in 584. His father Khattab ibn Nufayl belonged to the Banu Adi tribe while his mother Hantama bint Hisham belonged to the Banu Makhzum tribe. Umar once said: "My father was a ruthless man. He made me work very hard. If I didn't work enough, he would beat me. Thus, I used to work until I was exhausted." Khattab was a prominent arbitrator in his tribe thanks to his intelligence.
Although literacy among Arab tribes was not very common, Umar managed to learn to read and write in his youth. He was among about 20 literate people in Mecca before Islam. Umar liked reading poetry and was an influential speaker.
He also enjoyed women and drinking before he converted to Islam. He was also an active man, often participating in riding and wrestling.
When we combine his listed characteristics, we can easily come to the conclusion that he was an intelligent and strong man.
Conversion
Like many other leaders of the Quraysh tribe, the notables of Mecca, Umar did not listen to what Muhammad tried to teach. He refused the new faith and tortured Muslims in order to show his loyalty to the ancient traditions.
According to the famous anecdote, Umar wanted to kill the prophet and decided to go to his house. Along the way, somebody told him that his sister Fatima and his brother-in-law Said had converted to Islam and were reading the Quran at home.
Umar changed course and headed to his sister's, where he caught his sibling and her spouse reading lines from the Quran. He was so angry that he beat the two of them without hesitation or mercy. Yet, Fatima did not back down and had enough courage to stand up Umar, explaining that both of them had accepted the teachings of Muhammad and had converted to Islam. After his sister's speech, Umar softened his attitude and asked her to read the Quran to him. After listening to the recitation of the Quran for a while, Umar made up his mind and went to the prophet to learn how to become a Muslim.
When the two met, Umar told Muhammad that he came to obey God, the prophet and the teachings that God had sent. Muhammad prayed for him and caressed his chest.
During prophet's time
Umar became one of the best companions of the prophet after his conversion. He joined the hajj, the obligatory pilgrimage of Muslims to Medina from Mecca, with 20 members of his family and resided in Quba like many other Muhajirun, Meccan Muslims moving to Medina with Muhammad. He used to visit Medina very often to stay with the prophet.
Umar was also a good "mujahid," or warrior for the faith. He joined every battle led by the prophet himself. He also received some other military duties. Likewise, the prophet relied on him during diplomatic matters. He received the allegiance of the women in both Medina and Mecca after the conquest in the name of the prophet.
Umar became a relative to the prophet when his daughter Hafsah married Muhammad in 625.
When Muhammad died, Umar could not hide his feelings and said: "Muhammad is alive. God will send him again and cut the limbs of those who say that he is dead." Abu Bakr calmed him and they discussed the successor of the prophet. Eventually, Abu Bakr was chosen as the Leader of Believers with the help of Umar.
The second caliph
Although he was second after Abu Bakr, many historians think that Umar was the real leader shaping the caliphate. In Abu Bakr's time, state affairs had yet to be thoroughly formulated, though Abu Bakr was clearly the leader of the believers. Umar served as a military advisor and a judge during Abu Bakr's time.
Abu Bakr won the Muslims' approval and selected Umar as his successor. After Abu Bakr's death, Umar started a series of actions that enabled him lay the grounds for the first Muslim empire in history.
Umar's statesmanship is famous among Muslims. Abu Bakr wanted to continue his business as a merchant while he was the caliph. Umar convinced him not to do so and made him accept a salary from the treasury.
Umar held onto this belief during his caliphate, too. He was firm in his point of view that the statesmen shouldn't do personal business while acting as representatives of Muslim society. He never accepted any gifts, saying that those gifts would not be presented to him if he were not the caliph.
The Muslim army conquered many territories, including what are now the upper part of Iraq, all of Syria, Palestine, Egypt, Iran, Azerbaijan and some provinces of Byzantine Anatolia while Umar was caliph. These conquests raised some financial problems, such as the division of the vast spoils. Furthermore, the relations of the conquerors with the non-Muslim residents had to be handled with great care. Umar held a great meeting with his governors in Syria and created strict rules for social and financial questions. Umar is the first caliph to order the Islamization of conquered lands, including convincing the people of the newly conquered territories to accept Islam, to move a Muslim population to those territories and to establish civil structures there.
Umar also had Greek and Persian texts translated into Arabic and had the parts of the Quran merged. He also prevented any other written material from rivaling the Quran. In Umar's time, Arabic script was standardized and its initial calligraphic characters emerged.
Death
Umar had a dream of an inner land without a non-Muslim population. He moved the Jewish and the Christians in the Hejaz to Syria after paying for their lands. He did not want to allow foreigners entry into Medina. However, Medina citizens sought foreign craftsmen to make their daily home materials. So he listened to the people of the city and allowed foreigners to live and work in Medina.
Unfortunately, a foreigner, former Sassanian soldier enslaved during the war, Piruz Nahavandi, who had been working in Medina for the Basra governor, Mughira ibn Shuba, killed Umar while he was praying at the mosque. The slave and the governor had been arguing about the slave's wage. Umar told Nahavandi that he would solve the problem. He advised the slave owner to raise his wage. However, Nahavandi refused to wait for the solution to his financial situation and took his anger out on the caliph. A sign of justice was killed while he was trying to establish justice in a financial problem between two men.