Charles Ellicott Commentary 1 Kings 1:5

"Then Adonijah the son of Haggith exalted himself, saying, I will be king: and he prepared him chariots and horsemen, and fifty men to run before him." — 1 Kings 1:5 (ASV)

Adonijah (my Lord is Jehovah), David’s fourth son, born in Hebron (2 Samuel 3:4), at least thirty-three years before. From the words of Solomon in 1 Kings 2:22, we may gather that he claimed the throne as being now the eldest son. Hence it is probable that Chileab (or Daniel, see 2 Samuel 3:3; 1 Chronicles 3:1), the second son, was dead, as well as Amnon and Absalom. The similarity between Adonijah and Absalom, in respect of personal beauty, favor with a too-indulgent father, ambition, and trust in popularity, is evidently suggested by the narrative, which places them in close connection, although born of different mothers.

The means, moreover, which Adonijah employed—the bodyguard of fifty men and the maintenance of “chariots and horsemen”—are exactly imitated from the example of Absalom (2 Samuel 15:1); and we note that the festal sacrifice, with the support of two important leaders in peace and war, recalls the same model. But Adonijah hardly shows the craft and ruthless determination of the elder rebel. His attempt on the crown seems crude and ill-planned in conception, and wanting in promptness of action.