The Basilica di San Lorenzo (Basilica of St. Lawrence) is one of the largest churches of Florence, Italy, situated at the centre of the main market district of the city, and it is the burial place of all the principal members of the Medici family from Cosimo il Vecchio to Cosimo III. It is one of several churches that claim to be the oldest in Florence, having been consecrated in 393 AD, at which time it stood outside the city walls. For three hundred years it was the city's cathedral, before the official seat of the bishop was transferred to Santa Reparata. San Lorenzo was the parish church of the Medici family. In 1419, Giovanni di Bicci de' Medici offered to finance a new church to replace an eleventh-century Romanesque rebuilding. Filippo Brunelleschi, the leading Renaissance architect of the first half of the fifteenth century, was commissioned to design it, but the building, with alterations, was not completed until after his death. The church is part of a larger monastic complex that contains other important architectural and artistic works: the Old Sacristy by Brunelleschi and having interior decoration and sculpture by Donatello; the Laurentian Library by Michelangelo; the New Sacristy based on Michelangelo's designs; and the Medici Chapels by Matteo Nigetti. History The Basilica of San Lorenzo is considered a milestone in the development of Renaissance architecture. The basilica has a complicated building history. The project was begun around 1419, under the direction of Filippo Brunelleschi. Lack of funds slowed the construction and forced changes to the original design. By the early 1440s, only its sacristy (now called the Old Sacristy) had been worked on because that was being paid for by the Medici. In 1442, the Medici stepped in to take over financial responsibility of the church as well. After Brunelleschi's death in 1446, the job was handed either to Antonio Manetti or Michelozzo; scholars are uncertain which. Although the building was largely completed by 1459 in time for a visit to Florence by Pius II, the chapels along the right-hand aisles were still under construction during the 1480s and 1490s. By the time the building was completed, aspects of its layout and detailing no longer corresponded to the original plan. The principal difference is that Brunelleschi had envisioned the chapels along the side aisles to be deeper than those built and he intended them to resemble the chapels