Valentine's Day is celebrated on February 14th and is a day to honor love and Saint Valentine. It originated from a Christian priest named Valentine who secretly married couples against the orders of Emperor Claudius. When Claudius discovered this, he had Valentine arrested and sentenced to death. In prison, Valentine fell in love with his jailor's daughter and wrote her a farewell letter signed "your Valentine" before being executed. Today on Valentine's Day, people express love by sending cards, flowers, gifts, and sharing meals together. It has become one of the most popular commercial holidays in countries like the US where over $18 billion is spent annually on related items.