The kingdom of Israel splits into two separate nations after the death of King Solomon. His son Rehoboam ascends to the throne and when the people ask him to not be a dick like his dad. But his friends goad him into doubling down on his dickishness. He should have listened to Nancy Reagan and just said no to peer pressure!
So Jeroboam comes back from Egypt to take control of the northern kingdom of Israel while Rehoboam maintains control of the southern kingdom of Judah (oh yeah, and Benjamin).
And Jeroboam decides to make some golden calves. Why would he do that? Didn't he know golden calves are bad? Does he not read his scriptures? Or is there something else going on here? Why do birds suddenly appear every time you are near? Is that like a medical condition? Are you giving off avian pheromones or something? You should get that checked out.