Known as Brixia by the Romans, before becoming a free commune during the Middle Ages and then coming under the rule of the della Scala and subsequently the Visconti family, Brescia finally joined the Republic of Venice in 1428. Archaeological excavations have unearthed the remains of the Forum, the ancient theatre and the Capitoline Temple, while the largest and most important buildings of the historical centre date back to the flourishing Venetian period when the city became enriched with artistic contributions from the lagoon. The Loggia, on the Renaissance-style square that bears the same name, is probably the most valued monument in the city. The former institutional headquarters during La Serenissima, and today the headquarters of the city, it displays Palladian architecture and reaffirms the political domination of Venice. A magnificent example of this school of colour originating in Veneto, the Polyptyque Averoldi, painted by Titian in 1522, is kept in San Nazaro e Celso Church.