The conquest of the two empires
Within five years of taking the caliphate, Umar's armies had defeated the two great powers of the day: the Byzantines at Yarmouk (15 AH / 636 CE) under Khalid ibn al-Walid and the Sasanian Persians at Qadisiyyah (15 AH / 636 CE) and Nahavand (21 AH / 642 CE). The Byzantine Levant — Damascus, Hims, Antioch, Jerusalem — fell to the Muslims; the Sasanian capital Ctesiphon was taken in 16 AH; Egypt was opened by Amr ibn al-As in 20 AH. The pace was unprecedented. Umar's own correspondence with his commanders (preserved in many sources) shows the strategic mind behind it.
The opening of Jerusalem
When Jerusalem was being negotiated for surrender in 17 AH, the Patriarch Sophronius requested that the caliph come in person to receive the city's keys. Umar travelled from Madinah with a single servant, taking turns riding the one camel they shared. He entered Jerusalem in a patched cloak. He visited the Holy Sepulchre as a guest; when the time for prayer came, the Patriarch invited him to pray inside, but Umar declined, fearing later Muslims would convert the church into a masjid. He prayed outside on the steps. The Pact of Umar (the Ahd 'Umar) — the surrender treaty preserving the Christian community's churches, lives, and freedom of worship in exchange for jizya — became the template for non-Muslim status under Muslim rule for centuries.
The Hijri calendar — Umar's decision
When the administration grew complex enough to need dating documents, Umar gathered the senior Companions to decide what year to call 'year one'. Several options were proposed: the year of the Prophet's birth, the year of the first revelation, the year of his death. Umar — and Ali in some narrations — argued for the year of the Hijra, because the Hijra was the year a community of believers established a polity where they could practice their faith openly. The decision was made; the Hijri calendar starts from the Hijra (1 AH = 622 CE) and the new year begins with Muharram, the month after the Hijra.
The diwan and the year of Ar-Ramadah
Umar instituted the diwan — a state register listing every Muslim and the stipend due to them from the state treasury, calibrated by closeness to the Prophet ﷺ in faith and service. The year 18 AH brought the famine of Ar-Ramadah ('the year of ash') in the Hijaz. Umar refused to eat anything beyond what the poor were eating: dry bread and olive oil. His belly rumbled audibly during sermons. He addressed his stomach: 'Rumble or not, by Allah, you will not taste fat until the people of Madinah taste it.' Aid caravans were ordered from Egypt and Syria; the famine ended when the rains returned. Umar's personal asceticism during state-wide hardship is a recurring template in later Islamic governance literature.
His night patrols
Umar walked the streets of Madinah at night to check on the people. In one famous narration, he passed a tent and overheard a woman calming her crying children: she had nothing to feed them, so she put a pot of stones on the fire to make them think food was coming. Umar walked through the night to the storehouse, lifted a sack of flour onto his own back (refusing his servant's offer to carry it), brought it to her tent, and cooked the meal himself. When the servant tried to help, he said: 'You will not bear my burden on the Day of Judgement; let me bear my own.'
His assassination
Umar was assassinated in 23 AH while leading the Fajr prayer in the Prophet's Masjid. The assassin was Abu Lu'lu'a, a Persian Christian slave with a personal grievance, who concealed a poisoned dagger and stabbed Umar six times during the prayer. Umar lived for several days. On his deathbed he appointed a council of six senior Companions — Uthman, Ali, Talha, Zubayr, Sa'd ibn Abi Waqqas, and Abdur-Rahman ibn 'Awf — to choose the next caliph from among themselves within three days. He instructed his son Abdullah to be present in the council but not eligible. He asked Aisha for permission to be buried beside the Prophet ﷺ and Abu Bakr; she granted it.
Reflection
Umar's caliphate is the closest the world has ever come to a state run by a single principle — that the leader is accountable, both to Allah and to the most ordinary citizen. The empire he built was vast; the man who built it had only two cloaks, walked behind his caravan during peacetime, and refused to taste fat in a famine. He is studied in modern political science precisely because he proved that scale and humility are not incompatible — they only require a leader for whom the relationship with God is not theatre.
Primary sources
- Sahih Bukhari 3700 (the death of Umar, with full narration)
- Sahih Muslim 567 (Umar at the Black Stone)
- At-Tabari, Ta'rikh ar-Rusul wa-l-Muluk (the long chapters on Umar's caliphate)
- Ibn Sa'd, Tabaqat al-Kabir (the entry on Umar)
- Ibn al-Jawzi, Manaqib Amir al-Mu'minin Umar ibn al-Khattab