1 Kings 14:30

And there was war between Rehoboam and Jeroboam all their
days.
] For though Rehoboam did not enter into an offensive war, and attack the children of Israel, being dissuaded from it by Shemaiah the prophet in the name of the Lord, yet he might maintain a defensive war; and though there were no pitched battles between them as afterwards, in his son's time, yet there might be skirmishes and bickerings on the borders of their countries.