Age at the Acceptance of Islam

After Hazrat Khadijah (ra), Hazrat Ali (ra) was the first to accept Islam. At the time, he was 13 years of age and according to other narrations, his age has been reported as 15, 16 and 18.

(Ibn Abd al-Barr, Al-Isti‘ab fi Ma‘rifat al-Ashab, Vol. 3, Dhikr Ali bin Abi Talib [Beirut, Lebanon: Dar al-Kutub al-Ilmiyyah, 2002], 200)