Ammar ibn Yasir

Ammar ibn Yasir (Arabic: عَمَّار بْن يَاسِر, romanized: ʿAmmār ibn Yāsir; c. 567/570 – July 657 CE) was a Sahabi (Companion) of the Islamic prophet Muhammad, and a commander in the early Muslim conquests. His parents, Sumayya and Yasir ibn Amir, were the first martyrs of the Ummah. Ammar converted to Islam by the invitation of Abu Bakr and was amongst the muhajirun. After the migration to Medina, he participated in building the Prophet's Mosque and fought in most of the early Muslim expeditions.

He fought in the Ridda wars under Caliph Abu Bakr (r. 632–634) and in the Muslim conquest of Iran under Caliph Umar (r. 634–644). Ammar served as governor of Kufa under Umar. Following Uthman's assassination, Ammar became a devout partisan of Caliph Ali (r. 656–661) and died while fighting on Ali's side in the Battle of Siffin.

Source: Wikipedia — https://en.wikipedia.org/wiki/Ammar_ibn_Yasir