Hope from Allah that you are in good health and may He keep you in good health. The question is whether Hazrat Ali had pledged (Bai'ath) allegience with the previous 3 Khaleefas or no? Please quote references from Qur'an, Hadees and History and reply in both the circumstances.
I asked this because I wanted to have knowledge about this and so far I could not find from anybody. You will be greatly appreciated if you please reply this question.
Yes! it is clearly mentioned in explicit authentic Ahadees and books of History that Hadhrath Ali Radhiyallahu Anhu had made allegiance (Bai ath) with earlier three Khaleefas. Further it is mentioned by Hazrat Ali Radhiyallahu Anhu himself about taking Bai ath.
Refer THAKMILA 102/6, THAREEKHUL ISLAM LIZ ZAHABI 641/3,639/3.
Allah knows best.