2 Chronicles 13:2 (KJV)

Now in the eighteenth year of king Jeroboam began Abijah to reign over Judah.

He reigned three years in Jerusalem. His mother’s name also was Michaiah the daughter of Uriel of Gibeah. And there was war between Abijah and Jeroboam.

And Abijah set the battle in array with an army of valiant men of war, even four hundred thousand chosen men: Jeroboam also set the battle in array against him with eight hundred thousand chosen men, being mighty men of valour.

And Abijah stood up upon mount Zemaraim, which is in mount Ephraim, and said, Hear me, thou Jeroboam, and all Israel;