What was the name of the first family to take power after murdering the last of the four rightly guided caliphs?

Lol it is wrong question ummayed didnt murder the 4 caliphate, the fisrt abu baker died normal death, the 2nd caliphate Omar ibn Alkhatab was killed by Piruz Nahavandi who wasnt a muslim in the first place he wasnt even arab, the 3rd caliphate is othman ibn affan assassinated by ignorant muslims who sieged his house other sahaba stood to defend him one of which Hassan and Hussain the prophet grandchildren sons of Ali, the 4th caliphate is Ali bin abi talib the prophet cousin and son in law was killed by group of ignorant muslims from the Kharijites. and it have nothing to do with the ummayids