Saint George’s Day, also known as the Feast of Saint George, is the feast day of Saint George as celebrated by various Christian Churches and by the several nations, kingdoms, countries, and cities of which Saint George is the patron saint including England, and regions of Portugal and Spain (Catalonia and Aragon).
Tradition tells that a fierce dragon was causing panic at the city of Silene, Libya, at the time Saint George arrived there. In order to prevent the dragon from devastating people from the city, they gave two sheep each day to the dragon, but when the sheep were not enough they were forced to sacrifice humans instead of the two sheep. The human to be sacrificed was elected by the city’s own people. The king’s daughter was chosen to be sacrificed but no one was willing to take her place. Saint George saved the girl by slaying the dragon with a lance. The king was so grateful that he offered him treasures as a reward for saving his daughter’s life, but Saint George refused it and instead he gave it to the poor. — Wikipedia