What evolution did the Islamic civilization go through from Muhammad to the end of the caliphate?

Question

I know that Muhammad had not designated a sucessor to the Umma (religious community) and the Sunnis didn't believe that he did. Shiites believed that at Ghadir Qumm he designated Ali ibn Abi Talib (wasn't that his cousin?) The Khalifa Rasul Allah: The Successor to the Apostle of God. The Rashidun: The rightly guided caliphs Abu Bakr, Ummar, Uthman, and Ali. I know that caliphs were to be nominated by the elders of the community and confirmed by bay'a (the community at large).

Please clear this stuff up...I'm very confused...I know it was chaotic. Thanks (btw, my connection sucks...I've been trying to google stuff but it won't go through).

Answer 1

well muslims believed that abu bakr was the first one of prophet muhamed dead who deserve to be the leader of the ummah
after that omar came after the death of abu bakr
then others
in time of fight between osman and ali who would be the leader of the umah shea thought ali is the cousin of prophet muhamed and he is better than all those people

i think this is stupid fight in matters never worth to discuss about