Who is the builder of the Leaning Tower of Pisa?

Answer 1

We don't know because in middle ages the architect was not considered so important as it will be in renaissance. We only know architect who signed their works, like we know for the Cathedral and the Baptistery in the same square.

We don't know for the Cemetery and for the Bell-tower. But, if for the cemetery we have some hints in the old documentation, there is nothing about the tower.

Giorgio Vasari, an architect and writer of XVI century, said that the tower has been built by Bonanno Pisano. For centuries people agreed with him without proofs.

In XIX century a stone with Bonanno's name has been found near the tower and they thought it was the proof they needed, so they put it inside the bell-tower.

Nowadays scholars studied about it. We know that Bonanno was in Pisa in 1181 creating a bronze door for the Cathedral, about the same time of the construction of the tower (1173). About the stone with his name, the ground all around the cathedral was filled with graves until 1277, when began the construction of the cemetery building.

After all those years we still don't know.

Piero Pierotti, a modern scholar, think that a possible candidate can be Diotisalvi, author of the Baptistery (1152) and possibly other buildings in Pisa that have a lot of things, architecturally speaking, in common.