Porphyry columns, called of the Pisans

To either side of Door of Paradise of the Baptistery, facing the cathedral, are two massive red porphyry columns, testifying to a historic alliance between Pisa and Florence. In 1117, the city of Pisa decided to donate the two precious columns to the Florentines, as thanks for the support received in a time of war. Just prior, Pisa had been engaged in a conflict with the Saracens, played out in the Balearic Islands of Spain for the dominion of those seas. This meant that Pisa was left in a weakened state of defences, and the city feared an invasion of from nearby Lucca. It was Florence that joined in aid, and the columns are part of the booty from resulting inter-city battles, won by Pisa, who in turn donated them to their allied city. The columns were first placed in the area between the Baptistery and the Cathedral, commonly known as "Paradise": one of the most important spaces in the religious and civil life of Florence.