Uthman ibn Ali
According to the report which has mentioned the age of 'Uthman b. 'Ali, 21 years old at the time of martyrdom.  After the martyrdom of non-Hashemite companions of Imam al-Husayn, Banu Hashim went to the battlefield. The first person from among the children of Ali who went to the battlefield was Abu Bakr ibn Ali. After him, according to a report, it was 'Abd Allah and Ja'far, brothers of 'Uthman from the same mother. After them, Uthman went to the battlefield. Khawli ibn Yazid al-Asbahi shot an arrow at 'Uthman’s forehead and throw him down the horse. Then, a man from Banu Darim tribe beheaded him.