Did the Battle of Walaja, after the death of the Prophet, may God’s prayers and peace be upon him, lead to the emergence of the Shiites during the reign of Abu Bakr Al-Siddiq, may God be pleased with him?

The Battle of Walaja took place in Safar of the twelfth year of the Hijra, as part of the conquests of Iraq, and it was not the cause of the emergence of the Shi'a. The Shi'a did not emerge during the time of Abu Bakr; rather, the Ummah was united. Their emergence occurred after the killing of Uthman and the division of the Muslims, when they split into those who supported Uthman and those who supported Ali. They were not called "Imamiyyah" or "Rafidah" until after Zayd ibn Ali's uprising in Kufa and his prayers for mercy upon Abu Bakr and Umar. Some rejected him and were called "Rafidah," while those who supported him were called "Zaydiyyah."