1 Kings 12:1-33
Because Solomon had rejected God in favour of the gods of his wives Israel was divided into two kingdoms. Rehoboam was Solomon's son and heir to the throne. Since the big building projects of the Temple and the Palace were done the people asked Rehoboam for a tax break. Rehobaom heard the advice from the wise advisers to the wisest king ever (Solomon) and heard the advice of his friends who had no experience whatsoever. Probably wishing to impress his friends, he chose their bad advice and threaten the people.
That went over about as well as you'd think and the people basically said, "screw you" and went back to Israel and separated from Judah, the only tribe willing to put up with Rehoboam as king. Rehoboam retreated back to Jerusalem to recuperate and then mustered up some forces to attack Israel. He was about to attack when the prophet Shemaiah told him not to because it was God's will that Israel split and, in the first wise move he did as king, Rehoboam goes back home
Meanwhile, Israel names Jeroboam king. He was one of Solomon's officials and while out in town a prophet came to him and told him that God was going to give him 10 nations to rule over. When Solomon heard of this he tried to kill him but Jeroboam ran away and remained in hiding until Solomon died.
Jereboam did not want Judah to have any influence over the rest of Israel because he worried that they would decide to follow Rehoboam again and kill him. To stop any influence he decided to make a place of worship in his nation so that they would not have to go to Jerusalem to worship. The problem is he did not create a place to worship God but made two golden calves to worship. He claimed that they were the gods that led them out of Egypt and the people sacrificed and bowed down to them.
Because of this idol making Jeroboam was told by God that all his male heirs would be killed. Jeroboam would reign 22 years until he died. Rehoboam reigned 17 years in Jerusalem. He also set up areas to worship idols and so God allowed the Egyptians to come and ransack them stealing many things from the temple. A spree of bad kings would come to power in both Judah and Israel. Prophets were continually sent to try and bring the people back to God.