St. Ambrose is the patron saint of Milan and the city honors the occassion of his death every December 7. In medieval times, Ambrose was the bishop of Milan and he is an important figure in the city's rich history. The official religious holiday is celebrated by most Milanes with visits to church, special evening masses, and celebratory dinners. The largest service takes place at the magnificent Duomo. Most businesses close for the day. Events are free.