2 Chronicles 11:21

And Rehoboam loved Maachah the daughter of Absalom above all his wives and his concubines: (for he took eighteen wives, and threescore concubines; and begat twenty and eight sons, and threescore daughters.)

He took eighteen wives, and threescore concubines. This royal harem, though far inferior to his father's, was equally in violation of the law, which forbade a king to" multiply wives unto himself."