Miqdad b. 'Amr (Miqdad b. Aswad al-Kindi) was among the seven people who believed in the Prophet (s) from the beginning of his mission and became Muslim. After the Prophet (s) passed away, Miqdad did not pay allegiance to Abu Bakr and sided with 'Ali (a) during the 25 years before he assumed the caliphate.
'Ammar b. Yasir was one of the first people who believed in the Prophet (s) and immigrated to Ethiopia with the first group of Muslims and after the Prophet (s) immigrated to Medina, he joined the Prophet (s). After the Prophet (s) passed away, Ammar stood in defense of the Ahl al-Bayt (a) and 'Ali (a). Under the rule of 'Umar b. al-Khattab, he became the governor of Kufa for a period of time, but since he was just and lived a simple life, some tried to get him dismissed. He returned to Medina and stood with 'Ali (a) and benefited from him.
Maytham al-Tammar al-Asadi al-Kufi was one of the special companions of Imam 'Ali (a), Imam al-Hasan (a) and Imam al-Husayn (a). He was one of the Shurtat al-Khamis which was a group of men who promised Imam 'Ali (a) to help him until their last breath of life.
Muhammad b. Abi Bakr (a son of the first caliph) was born in 10/631. He was among the special companions of 'Ali (a) who believed that the previous caliphs had taken the right of 'Ali (a) and said that there was no one more deserving of the caliphate than 'Ali (a). He became the governor of Egypt in the month of Ramadan36/657 and was killed by Mu'awiya army in Safar of 38/658.
Uways al-Qarani, (Uways b. 'Amir al-Muradi al-Qarani) was a famous ascetic who converted to Islam at the time of the Prophet (s). Uways was among the special companions of 'Ali (a) who gave allegiance to him and promised to defend him until the last moments of his life, and in doing so, would never turn his back from the enemy [i.e. escape the enemy].