Construction of the bell tower, or campanile, was begun in 1334 by Giotto (1266- 1337), one of the most important figures in the history of Italian art. He was recognised by his contemporaries as the most revolutionary and versatile artist of his age; his paintings reveal a highly innovative three-dimensional treatment of space and a realisitic conception of bodies that was a marked contrast to the techniques of the medieval world (see for example his Expulsion of the Devils from Arezzo). He, however, died before the project was completed and it was continued by, among others, Andrea Pisano. The statues that line the bottom of the campanile are copies of the originals, which now stand in the Museo dell'Opera; Donatello and Pisano himself are some of the artists to whom they have been attributed. It is fascinating to imagine how these buildings must have looked when they were first unveiled to the public. The white marble must have gleamed beautifully then- more than five hundred years of wear has taken its toll and now the marble has turned a slight greyish colour in places.