King Solomon marries 600 women who in turn lead him away from the LORD. Solomon follows after the gods of his wives. Judgment from the LORD includes the tearing / dividing of the kingdom.
Jeroboam harasses Solomon, and ends up fleeing for his life.
Solomon’s successor to the throne of Israel is his son, Rehoboam. This young man chooses to defy the wishes of the people of Israel (to go easy on them as his father, Solomon, worked them hard).
Rehoboam tells them his finder is thicker than his father’s waist and they can expect to be worked harder!
Led by Jeroboam, the people of the North (Israel) divided from the people of the South (Judah and Benjamin), led by Rehoboam.
Thus the kingdom was divided in two.