St. Mark's Square has always been the public center of Venice's political, religious and traditional festivals. It is the seat of all important Venetian government agencies. Since the 19th century, it has been the residence of the Archbishop. It is also the site of many Venetian festivals. St. Mark's Square is a rectangular square surrounded by the Duke's House, St. Mark's Cathedral, St. Mark's Bell Tower, the new and old Executive Mansion Building, the Napoleonic Wing Building connecting the two buildings, the quadrangular Bell Tower of St. Mark's Cathedral, the St. Mark's Library and the Venice Canal. The buildings around the square ranged from the Middle Ages to the Renaissance. It was only in 1177 that St. Mark's Square was expanded to its present size for the meeting of Pope Alexander III and Emperor Frederick I of the Holy Roman Empire. After Napoleon occupied Venice in 1797, he praised St. Mark's Square as "the most beautiful living room in Europe" and "the most beautiful square in the world"