The basilica of San Lorenzo, in the piazza of the same name in the center of town, is one of the oldest churches in Florence. Its thousand-year history is also that of the Florentine Christian community, and is closely connected to the triumphant rise to power of the Medici dynasty that chose it as the family church.
At the start of the 1400s, in the original building, there was already a Medici chapel, afterwards called the Sagrestia Vecchia or Old Sacresty, designed by Brunelleschi for Giovanni di Bicci de'Medici, great grandfather of Lorenzo the Magnificent, the most famous member of the dynasty.
In 1418, the Medicis decided to being a serious renovation of the church to turn it into a family temple. The project was given to Brunelleschi who died, however, before being able to finish it.
Inside, though, the Brunelleschi touch is obvious: the huge space with its imposing dimensions, is governed by a scheme of controlled proportions and precise mathematical ratios. It can truly be considered a Renaissance architectural manual, both for its use of classical elements derived from ancient architecture, such as the round arches or columns with Corinthian capitols, as well as for the perfect measures of its spaces.
From the transept on the left, you enter Brunelleschi's Sagrestia Vecchia, built from the years 1421 to 1426. This is one of the works that best illustrates Renaissance architectural thought. The conception of space is simple and rigorous: the volume of the chapel is cubical, over which is the hemispheric dome divided into twelve slices. The area of the altar repeats on a smaller scale that of the main space. The contrast between the grey stone and light-colored stucco underlines the schematic design.
The decorations, such as the arabesques of blue cherubs and red seraphims, or the large round windows with Cosma and Damian, patron saints of the Medici family, were all done by Donatello. Not to mention the bronze doors that, by the way, were not appreciated at the time, being thought too modern with their exageratedly expressive and sometimes a trifle too agitated, figures.
The famous library of the Biblioteca Medicea Laurenziana is also part of the basilica complex, and the wide stairway at the entrance is one of Michelangelo's most original works. With its outsized, almost overflowing, dimensions, and the ingenious spiral shape of the stairs, it's a typical example of manneristic art and an introduction to Baroque expression.
The Library has the most prestigious collection of Italian manuscripts, a collection begun by Cosimo the Elder, one of the great Renaissance princely benefactors, and was later enlarged by Lorenzo the Magnificent. The space destined to hold this precious treasure trove of culture is one of the first examples ever of a library not pertaining to a religious institution.
Giorgio Vasari and Bartolomeo Ammannati, Medici architects after Michelangelo, completed the construction of the stairway, scrupulously following the Masters design.
The church buildings also contain the Medici chapels with their crypt, in which lie the remains of 50 members of the Medici family. Underneath the church are buried both Cosimo the Elder and Donatello.