Genealogists have related BaniShayban origin from Mosni-bin HarithaShaybani to prophet’s 19th ancestor called Nazar. Mosni-bin HarithaShaybani was a significant character who played a basic role in the events of early Islam. He managemd to earn reputation among Arabs due to his victory over the army of Iran in Zuqar battle, so that the first and second caliphs let him attack Iranian borders with other Islamic commanders.In addition to Zuqar battle under commandment of Mosni-bin HarithaShaybani, BaniShayban tribe had several battles with Shahrbaraz, Iranian self-styled king, including battle of chains and battle of Ullais during 11 to 14 A.H years. They participated in battle of the bridge with Abu Obadiah, another commander of the Muslim Arabs. They were also present at the battle of Boveib. The commander of Shaybanis attended the battle of al-Qādisiyyah with several injuries on his body and wished to participate in the battle of Jalula, but his life came to its end before that.In the days of Imam Ali, Shaybanis helped him and were his commanders, particularly in the battle of Siffin, because of being allied with the descendants of Abu Talib. Although some of them stood against Imam Ali, some others lost their lives guilty of friendship with him. They acquired high positions at the time of Umayyad and Bani Abbas and were even appointed in Armenia.The most important question is whether Shaybanis had any relationships with caliphs in early Islam; what role did they play in early Muslim conquests; and what positions were they assigned in the early centuries of Islam? The present study investigates the role of Shaybanis in Islamic era, particularly during early Islam as well as Umayyad and Bani Abbas reign.Keywords: BaniShayban, Mosni-bin Haritha, Iranian army, Umayyad, Bani Abba