when did they start building the leaning tower of pisa
August 14, 1173
title: Leaning Tower of Pisa text: Leaning Tower of Pisa The Leaning Tower of Pisa () or simply the Tower of Pisa ("Torre di Pisa" ) is the "campanile", or freestanding bell tower, of the cathedral of the Italian city of Pisa, known worldwide for its unintended tilt. The tower is situated behind the Pisa Cathedral and is the third oldest structure in the city's Cathedral Square ("Piazza del Duomo"), after the cathedral and the Pisa Baptistry. The tower's tilt began during construction in the 12th century, caused by an inadequate foundation on ground too soft on one side to properly support the structure's weight. The title: Leaning Tower of Pisa text: have toppled. In 1272, construction resumed under Giovanni di Simone, architect of the Camposanto. In an effort to compensate for the tilt, the engineers built upper floors with one side taller than the other. Because of this, the tower is curved. Construction was halted again in 1284 when the Pisans were defeated by the Genoans in the Battle of Meloria. The seventh floor was completed in 1319. The bell-chamber was finally added in 1372. It was built by Tommaso di Andrea Pisano, who succeeded in harmonizing the Gothic elements of the bell-chamber with the Romanesque style of the tower. There title: Leaning Tower of Pisa text: 14, 1173 during a period of military success and prosperity. This ground floor is a blind arcade articulated by engaged columns with classical Corinthian capitals. The tower began to sink after construction had progressed to the second floor in 1178. This was due to a mere three-metre foundation, set in weak, unstable subsoil, a design that was flawed from the beginning. Construction was subsequently halted for almost a century, because the Republic of Pisa was almost continually engaged in battles with Genoa, Lucca, and Florence. This allowed time for the underlying soil to settle. Otherwise, the tower would almost certainly title: Leaning Tower of Pisa text: his home town. A piece of cast bearing his name was discovered at the foot of the tower in 1820, but this may be related to the bronze door in the façade of the cathedral that was destroyed in 1595. A 2001 study seems to indicate Diotisalvi was the original architect, due to the time of construction and affinity with other Diotisalvi works, notably the bell tower of San Nicola and the Baptistery, both in Pisa. Construction of the tower occurred in three stages over 199 years. Work on the ground floor of the white marble campanile began on August title: Piazza dei Miracoli text: representations. Therefore, surveys of the Italian Renaissance usually begin with the year 1260, the year that Nicola Pisano dated this pulpit. The campanile (bell tower), commonly known as the Leaning Tower of Pisa, is located behind the cathedral. The last of the three major buildings on the piazza to be built, construction of the bell tower began in 1173 and took place in three stages over the course of 177 years, with the bell-chamber only added in 1372. Five years after construction began, when the building had reached the third floor level, the weak subsoil and poor foundation led to