Catherine of Aragon was a princess from Spain who was married to King Henry VIII of England a long time ago, like when your great-great-great grandparents were alive. They got married when they were both teenagers and they were happy together at first. But then, after many years, they had trouble having a baby boy. You see, back then, people thought it was really important for kings to have sons, because they would become king when their dad died. Henry really wanted a son, so he asked the Pope to let him get a divorce and marry someone else. But Catherine didn't want to get divorced because she loved Henry and she thought God wouldn't like it. So there was a big fight, and eventually Henry decided he didn't want to be married to Catherine anymore. He made himself the head of the church in England so he could get a divorce and marry someone else. Catherine was very sad about this and went to live in a castle far away. She died not too long after. Many people still remember her as a brave and kind queen who stood up for what she believed in.