Why did the ten northern tribes secede from Rehoboam?
The ten northern tribes seceded because Rehoboam refused to reduce the heavy tax burden Solomon had imposed. When they asked him to lighten taxes, he rejected that advice and threatened to tax them even more, so the northern tribes broke away and made Jeroboam their king.
Les explains that Solomon had taxed the people heavily, so they asked Rehoboam to lighten the load and said if he did, Israel would elevate him. Rehoboam rejected that advice and said to tax them even more. When he refused to lower taxes and keep peace, the ten northern tribes—all except Judah and Benjamin—seceded. They declared they would have their own king, and Jeroboam, not from the royal line, became king of the northern ten tribes. Rehoboam, Solomon's son, remained king in Jerusalem, where the temple was.