The Cathedral of Pisa as it can be seen today was completely rebuilt beginning in 1064 to replace an older edifice.

The present cathedral is a large basilica made up of five naves supported by columns. The three central naves terminate in an apse and transept which form the arms of a cross. The vast space of the basilica culminates in a colonnaded tribune over the central nave and choir pierced by double and triple mullioned windows. The central nave is also illuminated by a row of simple windows along its uppermost tier.
The original truss roof made of wood was in part replaced by an elegant coffered ceiling after a fire in the cathedral in 1595. At the crossing of the naves and transept large pilasters support an oval cupola surrounded  by a gothic loggetta which was added at the end of the 14th century.
The new cathedral took nearly a century to complete. The first architect, Buscheto, is buried in a fine sarcophagus inserted in the wall of the cathedral. Little is known about Buscheto’s life, but his epitaph describes him in glowing terms as the inventor of machines made of wood that were able to raise the heavy granite columns of the nave using a system of pulleys. According to contemporary sources these machines were so effective and simple to use that the columns could have been set up without any trouble by a handful of girls. Naturally this commentary was solely intended to celebrate the merits of the architect, as the construction sites of the period only employed grown men.
The architectural style of Buscheto shows his knowledge of the prototypes of the classical and early Christian Roman periods, the architecture of the Byzantine Empire and historic cities along the Adriatic coast such as Ravenna and Venice, unusual structural elements such as the acute arch recently introduced by the Normans to Sicily, and the geometric motifs of Islamic art. The stone carving inside the cathedral is prevalently of Roman inspiration, with large foliated capitals and little figurative decoration.
In a subsequent phase, beginning in about 1135, the west end of the cathedral was extended under the supervision of the architect Rainaldo, who designed the lower part of the façade employing a decorative repertoire filled with animals and symbolic elements in a graphic two-dimensional style. The forms are more dynamic and the color contrasts more accentuated in his work than that of his predecessors.
Beginning in about 1150 the upper part of the façade and the main bodies of the naves were finally completed under the direction of a third master architect, Guglielmo. His style was more plastic and his use of the drill can be seen in many of the elements in the façade, from the portals to the friezes decorated with scenes of animals and hunting scenes that run above the first-level galleries.
Around 1170 the sculpting of the fine marble façade with four orders of galleries was completed. Among the artists who participated in this last phase we find Biduino, who after this project was finished began working on the Leaning Tower.