Legend has it that St. Gregorio, even when he was the Pope, humbly served the meal to 12 poor persons everyday. One day, a miracle happened: an angel appeared at table and the Pope served him the meal as to everybody else. From that moment until 1870, the Pope used to serve meal to 13 poor persons every Holy Thursday. After, the custom was abandoned because it was believed that the 13th place had to be reserved for the angel only.