A bell tower built in stages
The Leaning Tower was planned as the bell tower of the cathedral on the Piazza dei Miracoli. It was built in stages, with long pauses, between the 12th and the 14th century. The ground gave way while the building rose, and the story of the tower is largely the story of this problem.
A few dates and names vary between accounts. Where that is the case, the main version comes first and the alternative follows.
Timeline
The main dates in order.
| Date | Event | Detail |
|---|---|---|
| 1064 | Cathedral founded | Consecrated on 26 September 1118 |
| 1152 | Baptistery founded | 15 August 1152 |
| 1173 | Work on the tower begins | 9 August 1173; some accounts following Vasari give 1174 |
| After the third ring | Building stops | The ground settles unevenly |
| 1275 | Work resumes | Under Giovanni di Simone and Giovanni Pisano; some accounts give 1272 |
| Mid 14th century | Belfry completed | Some accounts give 1370 |
| 1655 | Largest bell cast | About 3.5 tonnes |
| 1987 | World Heritage listing | The Piazza del Duomo is inscribed by UNESCO |
| 1990 to 2001 | Closure and rescue | Closed from early 1990, reopened in December 2001 |
Pisa tours and day trips
Guided visits and day trips to the Leaning Tower and the Piazza dei Miracoli, with live prices and availability.
Three phases of building
Foundations, a pause and a correction.
First phase: 1173 and the foundations
Work began on 9 August 1173. The foundations sat on weak ground, and after the third ring the work stopped because the soil settled.
Second phase: 1275 onward
Work started again in 1275, under Giovanni di Simone and Giovanni Pisano. The upper floors were built to compensate for the lean that had appeared. The belfry was finished around the middle of the following century.
The modern phase: 1990 to 2001
The tower was closed at the start of 1990, on 7 January. Engineers removed soil under the north side and regulated the groundwater. The reopening came in December 2001, on 15 December.
Why the tower leans →Who designed the tower?
Accounts name different architects.
Diotisalvi
Diotisalvi is considered the likely designer. He is also named as the original builder of the baptistery.
Bonanno Pisano
Another account attributes the design to Bonanno Pisano.
Guglielmo and Bonanno
The 16th-century writer Vasari credited Guglielmo and Bonanno and gave the year 1174. It is an old tradition and not the last word on who the architect was.
For the other buildings, the operator names Buscheto for the original cathedral and Rainaldo for its extension and façade. Nicola and Giovanni Pisano worked on the baptistery later. The square as a whole is covered on the page about the Piazza dei Miracoli.
The square around the tower
When the other buildings were founded.
Cathedral
Founded in 1064 and consecrated on 26 September 1118. The operator names Buscheto for the original building and Rainaldo for the extension and the façade. Giovanni Pisano made the pulpit between 1302 and 1310, according to the operator.
Baptistery
Founded on 15 August 1152 with Diotisalvi as the original builder. The pulpit is by Nicola Pisano and dates from 1260.
Camposanto and museums
The Camposanto dates from 1277. After a wartime fire and the removal of the frescoes, the preparatory sinopie came to light, and they have been in their own museum since 1979. The cathedral museum was redesigned and reopened in October 2019.
The Galileo legend
A famous story about the tower.
The story goes that Galileo Galilei dropped balls from the tower to test falling bodies. The Museo Galileo calls the experiment a legend and points to a later account by Vincenzo Viviani from 1654. Enjoy it as a legend, because no year is known for such an experiment.
History of the Leaning Tower of Pisa: frequently asked questions
When was the Leaning Tower of Pisa built?
Work began on 9 August 1173. It stopped after the third ring and resumed in 1275. The belfry was finished around the middle of the following century.
Who built the Leaning Tower of Pisa?
The architect is not settled. Diotisalvi is considered likely, another account names Bonanno Pisano and Vasari credited Guglielmo and Bonanno. Giovanni di Simone and Giovanni Pisano led the work from 1275.
Did Galileo drop balls from the tower?
The story goes that he did, but it is a legend. The Museo Galileo points to an account by Viviani from 1654.
When was the tower closed to visitors?
From 7 January 1990 until 15 December 2001.
Why did the building stop for so long?
The ground settled unevenly after the third ring was built, and work stopped. It resumed in 1275 with upper floors that compensate for the lean.