Abu Bahr[1] Al-Ahnaf ibn Qays (Arabic: الأحنف بن قيس) was a Muslim commander who lived during the time of Islamic prophet Muhammad.
[citation needed] After Muhammad's death in 632, a number of tribes rebelled for different reasons, al-Ahnaf and his people, however, remained Muslims.
[citation needed] When Umar ibn al-Khattab became caliph in 634, the Muslim conquests outside the Arabian Peninsula increased, and Al-Ahnaf encouraged his people to participate.
[citation needed] In 639, al-Ahnaf returned to Medina bringing news of the conquest of Tustar, and informing Umar of affairs in Persia.
[citation needed] Umar gave him permission to pursue Sasanian king Yazdgerd III, and put al-Ahnaf at the head of a Muslim army to complete the conquest of Khurasan in the last stages of its annexation.
With an army that was only a fraction of the enemy's, he managed to defeat the Persians in Battle of Oxus river, killing their leader, while the Turks retreated to their land.
[citation needed] Al-Ahnaf returned to Basra after the campaigns in Persia and remained serving Islam, until the time of the caliph Ali ibn Abi Talib (died 660) when the Muslims were split into two warring parties.