After centuries of barbarian invasions cultural life in Florence started again in the X-XI centuries. Florentine works of that period, like St John's Baptistery (XI century), built on preceding Roman remains, express strong links to classical models: the shapes are geometric, simple and immediately reveal, their rationality and how they aspire to perfect balance.
The building is the earthly image of a higher, divine reality, and for this reason tends to show itself in absolute, direct shapes. In the Romanesque of this sober, rigorous architecture there's no room for excessive ornaments and decorations and often the insides are just the essentiality of geometric volumes (see inside the Florence Cathedral). A distinctive element of Tuscan Romanesque, and especially of the Florentine one, is duotone obtained through the use of Carrara white marble and the green one from Prato.
The Baptistery comes across as a compact, imposing geometric volume. Its octagonal structure has a really strong symbolic value: the octagon represents the eighth day, the one outside human life's earthly cycle in which Christ rises and lives eternally and is an image associated with the rite of baptism since Early Christian times.
Outside, the famous bronze doors scan three fundamental steps in the history of this monument besides the evolution of figurative culture in Florence. Between 1330 and 1336, Andrea Pisano had created a first door in bronze with golden figures in relief, of a decidedly gothic type. Later in 1401, a competition was launched for a second door (and seems to be the first public competition in the history of art) and was won by Lorenzo Ghiberti with a work that was basically like the first one though with greater depth and naturalism.
But when in 1424 Ghiberti, having been assigned the project for the third door, presented his project it was clear to all concerned that this was something deeply different to what had been done before. The reliefs were bigger and all gold and the figures in the different tiles appeared in the same scale, for greater clarity and understanding. Ghiberti proved his ability in showing minimum details and in his varied representations of the human figure, but specifically introduced a new element, linear perspective, thus opening the door to the definite affirmation of the Renaissance.
Ghiberti had exceeded himself in what was then called the 'Door to Paradise' and his masterpiece conquered a place of honour on the portal in front of the Cathedral. To the sides there are two porphyry columns with a curious story. Of classical origins they were given to the Florentines by the Pisans in 1115 in thanks for Florence's help against the Muslims. But the columns are broken: the story says that when they reached Florence they were already broken and that the Pisans had covered them to hide the defect.
Inside a mosaic by Coppo di Marcovaldo reminds faithful of inexorable divine justice in a grotesque, excited representation of the Universal Judgement (1260-1270). This work with its monstrous figures and dramatic, intense narration was an important reference point for the Florentine art environment and Giotto, himself, in his Universal Judgement in Scrovegni Chapel in Padua, shows that he has learnt the lesson.