The area where the current St. Peter’s Square Fountain sits was very different at the beginning of the 16th Century. The square, at that time, was actually used for bullfights, thanks to the Borgia Pope Alexander VI, a Spaniard, who introduced the sport to Rome. The old square portico originally extended in front of the basilica almost to the obelisks.
A brief description has been left, by Burckard, a 15th/16th century writer, discussing the square during a Feast of St. John in 1500, “the area was boarded off from the corner of the Palace Guardians' block to the fountain built by Innocent [VIII], and from there right up to the church of San Martinello -- almost the whole center of the present square. Five or six bulls were released into the ring. Among many others, Duke Valentino entered on horseback, striking at the animals until he had killed them all."
Another account, praising the bullfights, comes from an ambassador from Epheus. The Turk was very impressed with Duke Valentino and Cesare Borgio, he wrote, “The Pope Alexander VI loves and is very much afraid for his son, the Duke, who is 27, with a good body, tall and well made, better than King Ferandin [Ferdinand], who, on horseback, in a game at St. Peter's in an enclosure made of planks, killed seven wild bulls, and fought like a tiger cutting a bull's head off with his first stroke, something all Rome considered marvelous."
Let’s focus on “Innocent’s Fountains, mentioned by Burkard above. This fountain as very new at the time of the description, described by another writer, “"In 1490, His Holiness [Innocent VIII] built a most noble fountain at the end of St. Peter's Square, with decorated marble tablets and two small round basins, one above the other, as you can see; everyone thinks there is nothing of its kind anywhere else in Italy." The position of the fountain is pinpointed exactly to its location as a result of a plant made of the square, two centuries later, when a massive reorganization took place. Bernini, at that time, moved the fountain a few yards closer to the basilica in order to line up the fountain with the obelisk as well as with the fountain that was planned for the opposite side of the square.
