When the Congregation of Fonts draws up a list of new fountains to be fed by the waters of the Acqua Vergine, whose design was commissioned of Giacomo Della Porta, a great fountain builder in Rome of ‘600, the noble Muzio Mattei who belongs to a family of dukes of Marchigiana origin controlling the economy on the left bank of the Tiber, protector of the Jewish community confined to the nearby ghetto, realises – we are in 1570 – that the square where his own palaces stand is excluded from the plan.
He starts exerting pressure on the authorities resulting in the deviation of the Acqua Vergine up to “Piazza Mattei” and offers, at his family’s expense, to pave the whole square and to guarantee its surveillance and cleanliness. The fact is that in the end not only was the construction of a fountain, assigned to the Florentine Taddeo Landini, from the plans drawn up by Della Porta, to be positioned right in the family square but on completion of the works, in 1584, this fountain, even though ornamental and not monumental, resulted in being the richest sculpture ever created by Della Porta.
The original project envisaged that four slender youths, carved in marble but subsequently created in bronze, should be pushing the dolphins into the higher basin of African marble; the dolphins, because of technical difficulties arising at the moment of their installation, were moved to the Fontana della Terrina that is today located in Piazza della Chiesa Nuova.
During a restoration asked for by Pope Alessandro VII Chigi, Bernini (for others it was Andrea Sacchi) added the bronze tortoise who give their name to the fountain. They are pushed up by slender youths to drink from the edge of the basin that collects the water from the spurt which then falls into the fountain below.
The tortoise have been stolen several times during the past centuries. In 1944 a rag man found them and gave them to the Town Council; after the last theft in 1981 four copies have replaced the three originals which are now in the Town Hall museum.
A popular legend tells of Duke Mattei who, compromised by debt and wishing to re-establish his prestige in the eyes of his future father-in-law and promised wife, made them look out of the palace window to admire the fountain which had been built overnight. He surprised them so much he was able to conclude the marriage that would otherwise have been broken off.
In order to preserve this memory he had the window walled up and to this day this is a characteristic of the facade. It’s a shame that this tale, apart from the exaggeration of the fountain being built in one night, holds no real truth: the building was in fact constructed several years after the fountain was installed.