2 Chronicles 12:13

So king Rehoboam strengthened himself in Jerusalem, and reigned: for Rehoboam was one and forty years old when he began to reign, and he reigned seventeen years in Jerusalem, the city which the LORD had chosen out of all the tribes of Israel, to put his name there. And his mother's name was Naamah an Ammonitess.

So Rehoboam strengthened himself in Jerusalem,.... Fortified that yet more for the defence of himself, after Shishak departed:

and reigned; twelve years more, for he reigned in all seventeen, and this was in his fifth year; of what follows in this verse,

See Gill on "1 Kings 14:21".