Early in the 15th century, Florence, where Giotto had worked, became the first great center of the Renaissance. There a group of young artists experimented with new techniques. The architect and sculptor Filippo Brunelleschi (1377?-1446) was a leader of the group.
Attempting to break with the Gothic traditions of building, Brunelleschi looked to classical architecture for inspiration. After studying Roman buildings, he developed a new approach to architecture. In 1421 he designed the first Renaissance building, the Ospedale degli Innocenti (Foundling Hospital) in Florence. The facade (front) of the building has a colonnade--a series of wide arches separated by slender Corinthian columns like those used in classical architecture. Between the arches are colored terra-cotta (hard-baked clay) medallions of babes in swaddling clothes made in the workshop of Luca della Robbia (1400?-82). Harmonious proportions distinguish Brunelleschi's architecture.
Brunelleschi devised a mathematical method for creating the illusion of depth on a flat surface. This method, called perspective, is based on the principle that objects appear smaller as they go farther into the background. It became a valuable tool to painters.
Brunelleschi was less successful as a sculptor than as an architect. In 1401 he competed with Lorenzo Ghiberti (1378-1455) for the commission to design a pair of bronze doors for the Baptistery of Florence Cathedral. The doors were to be carved in relief sculpture, in which the figures remain attached to a background. The subject chosen for the competition was the Sacrifice of Abraham. Ghiberti's design won.
Later, about 1435, Ghiberti designed reliefs for a second pair of doors for the cathedral. Impressed with the great beauty of the doors, Florentines called them the Gates of Paradise. A comparison of the two pairs of doors shows how the new ideas of the Renaissance influenced Ghiberti. In the earlier doors his designs are closer to the flat, patterned compositions of the Gothic style. The reliefs on the Gates of Paradise look much more realistic and are done in perspective. The human figures look more like classical sculptures.
Tommaso Guildi, nicknamed Masaccio (1401-28), was another member of the early Florentine group. He was one of the first painters to use perspective as a device to make his painting look more real. Masaccio went much further than Giotto in giving his subjects dignity and emotion. His compositions were always very simple, usually built up in geometric arrangements.
The most famous sculptor in the group was Donato di Niccolò di Betto Bardi, known as Donatello (1386?-1466). He studied human anatomy and classical sculpture. He was not content to follow formulas handed down from the Middle Ages. He and other Renaissance artists went directly to nature itself. Donatello's sculptures have a realism and freshness that came from his studies of live models.