I will make myself king - 1 Kings 1:5
As his father David days were coming to an end, Adonijah tried to boast himself as kings instead of the oppointed successor, Solomon.
Adonijah didn't hide his self ambition or shameless self-promotion
He setup an event to perform animal sacrifices with royal officals but did not invite Solomon or Nathan
Solomon quickly became king and then pardoned Adonijah as long as he was loyal to Solomon - 1 Kings 1:52-53
Adonijah couldn't let it go, he made a second attempt at the throne because of his stubbornness and self-protion, it cost him his life - 1 Kings 2:25