This church, with its facade that was never completed, was largely funded by the Medici, i.e. Cosimo the Elder. He donated the princely sum of 40,000 florins. Brunelleschi designed the church and the Old Sacristy. Later, Michelangelo Buonarroti built the New Sacristy on the east side of the transept. Buonarroti also designed the library in the adjoining inner courtyard. Michelozzo probably designed the first cloister (B on the floorplan below).
Video Google Earth San Lorenzo
Aerial complex of San Lorenzo
A. Old Sacristy (Brunelleschi)
B. Cloister (attributed to Michelozzo after 1457)
C. Laurentian Library (Michelangelo 1523-1529)
D. Cappella dei Principi (Chapel of the Princes by Buontalenti and others 1605-1737)
E. New Sacristy (Michelangelo)
The construction history of the San Lorenzo
One of the reasons behind the large number of churches that were built in the 15th century was the felt need of many rich families to be buried in a church. Each family wanted to have their own funerary chapel, and as close to the main altar as possible. The old San Lorenzo was considered ‘the ‘Duomo outside the walls’, and was even older than the Santa Reparata. According to the chronicles, the church was consecrated by St Ambrose in 393.
The district where the old San Lorenzo was located, the district of the Santissima Annunziata, was home to a large number of rich families including members of the Medici clan, such as Giovanni di’Averardo, a.k.a. Bicci, and his son Cosimo (the Elder). These rich families not only had much money, but also extensive influence in the city government, more specifically in the Signoria. The San Lorenzo chapter submitted a request to the Signoria for permission to build a new church. There was, however, a problem; a large number of houses had to demolished because the new basilica obviously had to be substantially larger. What would eventually prove impossible with the Santo Spirito, i.e. to turn the church around and build a beautiful square in front of the church (and the Arno), did succeed here. After the Signoria granted its permission, the foundations for the main chapel was already laid in 1419. We know for a fact that Brunelleschi did not become involved in the construction of the church until a later stage of the project.
Manetti writes that the “prior of the church – who was considered a person who was just as knowledgeable as other architects from his period – was appointed master builder. He started with the stone columns’ As we have already seen in the case of the Santa Maria Novella, churches were often built by clergy of the order that already had the requisite architectural experience. Filippo Brunelleschi obtained the commission to build the San Lorenzo via the ‘backdoor’: the construction of ‘his’ Old Sacristy. He had to take the columns into account that had already been built in the crossing. It was the Old Sacristy, an assignment from Bicci de Medici, that had made a great impression. This was the reason Filippo was commissioned to build the church as well. The Old Sacristy, which today appears to be an integral part of this church, was originally designed as a separate space. We will examine and discuss this sacristy when we enter the church.
Despite an auspicious start to the construction, financial problems soon arose. In the years 1420- 1435, most construction activities in Florence came to a halt. This was mainly due to the wars against Visconti of Milan and Lucca. Also, Cosimo the Elder was driven from Florence and did not return from his place of exile, Venice, until 1434.
Filippo’s Old Sacristy had been completed, but the walls of the transept’s chapels had only been erected to a height of 60 centimetres. When Cosimo and his money returned to the city, the building activities started making headway, albeit not immediately. The project was rather controversial, which explains why Cosimo, the sly fox, initially focused his attention on a new palace for his family and on the San Marco. Michelozzo built, among others, a monastery and a library for this church.
In 1440, the prior, Benedetto Schiattesi, convenes the council, the Gonfalone, to take a decision on the further construction of the San Lorenzo. There was no more money and the canons were all too eager to sell their rights to the chapels. Cosimo did not show up at this meeting. He did, however, make sure that everybody knew that he was willing to pay 40,000 florins for the construction, albeit on certain conditions. Two years later, on 13 August 1442, the Gonfalone reconvenes. This time to actually take a decision. And this time Cosimo did attend. The list of participants, including the prior, the cannons and the Medici supporters Piero de’Pazzi and Ugolino Martelli can still be found in the ricordi (minutes). Cosimo emerged victorious. In addition to the rights to some chapels, he also acquired the right to a tomb, directly below the crossing. The tomb had already been completed when Cosimo died in 1464. The rights to all the chapels have been meticulously recorded. Many opponents of the Medici lost their rights to the chapels in the transept. After all, these chapels were far too beautifully and prominently located. Clearly, they could not be granted to opponents of the Medici. There is one exception, the Rondinelli family (the chapel on the left that adjoins the main chapel. The Medici failed to acquire the rights to this chapel).
The transept and dome were completed even before Cosimo’s death. The remaining elements of the old San Lorenzo were demolished when the main altar had been completed in 1461. From then on, mass could be celebrated in the new section. In 1462, Pagno di Lapo is appointed the new campomaestro (master builder) of the San Lorenzo. Lapo took over from Manetti, who, prior to 1461, had built the dome as well as other elements. The remainder of the church, the nave, was built between 1460 and 1480 according to a design by Brunelleschi. After all, if one bay of the nave is known, the rest can be built based on that design.