1 Kings 1:5-7

5Then Adonijah the son of [David’s wife] Haggith exalted himself, saying, “I [the eldest living son] will be king.” So [following Absalom’s example] he prepared for himself chariots and horsemen, and fifty men to run before him.

6His father [David] had never rebuked him at any time by asking, “Why have you done this?” Adonijah was also a very handsome man, and he was born after Absalom.

7He had conferred with Joab the son of Zeruiah [David’s half sister] and with Abiathar the priest; and they followed Adonijah and helped him.