What happened to Solomon's kingdom as a result of his choice to turn away from God?

Answer 1

1Kings:11:31-37:

31: And he said to Jeroboam, Take thee ten pieces: for thus saith the LORD, the God of Israel, Behold, I will rend the kingdom out of the hand of Solomon, and will give ten tribes to thee:

32: (But he shall have one tribe for my servant David's sake, and for Jerusalem's sake, the city which I have chosen out of all the tribes of Israel:)

33: Because that they have forsaken me, and have worshipped Ashtoreth the goddess of the Zidonians, Chemosh the god of the Moabites, and Milcom the god of the children of Ammon, and have not walked in my ways, to do that which is right in mine eyes, and to keep my statutes and my judgments, as did David his father.

34: Howbeit I will not take the whole kingdom out of his hand: but I will make him prince all the days of his life for David my servant's sake, whom I chose, because he kept my commandments and my statutes:

35: But I will take the kingdom out of his son's hand, and will give it unto thee, even ten tribes.

36: And unto his son will I give one tribe, that David my servant may have a light alway before me in Jerusalem, the city which I have chosen me to put my name there.

37: And I will take thee, and thou shalt reign according to all that thy soul desireth, and shalt be king over Israel.

Answer 2

1) His kingdom was split in two after his death. God told him this would happen (1 Kings ch.11).

2) He was harassed by Hadad the Edomite (ibid).