The Basilica of Sant'Andrea is a Roman Catholic co-cathedral and minor basilica.It is one of the major works of 15th-century Renaissance architecture in Northern Italy. Commissioned by Ludovico III Gonzaga, the church was begun in 1462 according to designs by Leon Battista Alberti on a site occupied by a Benedictine monastery, of which the bell tower (1414) remains. The building, however, was finished only 328 years later. Though later changes and expansions altered Alberti's design, the church is still considered to be one of Alberti's most complete works. It looms over the Piazza Mantegna.