From the Archives - How the Baptistery of San Giovanni Acquired its Columns
The entrance to the Baptistery of the Church of San Giovanni in Florence sports spectacular bronze doors made by Lorenzo Ghiberti in the early fifteenth century, and is framed by two massive columns of porphyry. Now porphyry is a stone of such color and quality as to be termed “Imperial Porphyry,” and the columns are among the largest pieces known of this rare stone; apparently only Tamerlane’s sarcophagus in Samarkand is larger. How the baptistery acquired the columns is an interesting story.
Though later they would be at each other’s throats for generations, during the twelfth century Pisa and Florence, neighbors in Tuscany, were on friendlier terms. So much so, that the Pisans once asked the Florentines to guard their city while they were on an overseas expedition.
The tale is told by Giovanni Villani, in his New Chronicles on the history of Florence, composed early in the fourteenth century.
In the year of Christ 1117 the Pisans made a great expedition of galleys and ships against the island of Majorca, which the Saracens held, and when the said armada had departed from Pisa and was already assembled at Vada for the voyage, the commonwealth of Lucca marched upon Pisa to seize the city. Hearing this, the Pisans dared not go forward with their expedition for fear that the Lucchese should take possession of their city; but to draw back from their enterprise did not seem for their honor in view of the great outlay and preparation which they had made.
Wherefore they took counsel to send their ambassadors to the Florentines, for the two commonwealths in those times were close friends. And they begged them that the Florentines would please to protect their city, trusting them as their inmost friends and dear brothers. And on this the Florentines undertook to serve them and to protect their city against the Lucchese and all others.
Thus, the commonwealth of Florence sent thither armed men in abundance, horse and foot, and encamped two miles outside the city. In respect for the Pisan women they would not enter the city, and made a proclamation that whosoever [of the Florentine host] should enter Pisa should answer for it with his person. One man did enter the city and was accordingly condemned to be hanged. And when the old men who had been left in Pisa prayed the Florentines for love of them to pardon him, they would not. But the Pisans still opposed, and begged that at least they would not put him to death in their territory; whereupon the Florentine army secretly purchased a field from a peasant in the name of the commonwealth of Florence, and thereon they raised the gallows and did the execution to maintain their decree.
And when the host of the Pisans returned from the conquest of Majorca they gave great thanks to the Florentines, and asked them what memorial they would have of the conquest — the metal gates or two columns of porphyry which they had taken and brought from Majorca. The Florentines chose the columns, and the Pisans sent them to Florence covered with scarlet cloth, and some said that before they sent them they put them in the fire for envy. and the said columns are those which stand in front of [the Baptistery of the Church of ] San Giovanni.
Thus it was that, for the cost of keeping an army in the field for some months, plus one disobedient soldier hanged, Florence acquired two of the most impressive porphyry columns in the world, between which, more than a century later Ghiberti would work his own magic.