1 Kings 9-11: The Queen of Sheba visits. Solomon sins by accumulating gold, horses, and women.

Solomon expands his great and prosperous kingdom with armories, building projects, bridges, and international trade. In the process, he violates God's commands in Deut. 17 to NOT multiply gold, horses, or women -- which was the normal thing for a successful worldly king to do.
After the Queen of Sheba visits, she sees that his wealth, kingdom, and political brilliance has no equal.
However, his many wives lead Solomon to have mixed and weakened loyalties to God. As a result, God promises Solomon that the kingdom will be ripped from him -- but as a special gift of mercy to his father, David, Saul's son will be allowed to retain the largest tribe -- the one that will STILL (someday) be the tribe from which the coming Messiah will come.