Italy at the beginning of the 16th century was a battleground. Principal players included the Spanish, French, and the Pope. If the last figure seems a little incongruous you need to understand that the papacy then was a very different organisation to the one we know today. Pope Julius II actually led his troops into battle!
It all went horribly wrong for the Pope, Clement VII, in 1527. He was in league with the French against Charles V, the Holy Roman Emperor. Charles’ army defeated the French but his unpaid troops then rebelled and the sack of Rome followed. It lasted eight months, the population of the city dropped from 55,000 to 10, 000, and it marked the end of the High Renaissance. The Pope took refuge in Castel Sant’Angelo from where he eventually escaped and fled to the Umbrian city of Orvieto.
These events shook Clement VII and he saw Orvieto as a place of safety for the future. To ensure that in the event of a siege the town would not run out of water, he commissioned Antonio Sangallo the Younger to construct a well, and what a well Pozzo di San Patrizio is! It is over 175 feet deep with a diameter of 43 feet. But the really ingenious part of the design was the method for moving water to the surface; Sangallo built two ramps in a double helix around the central shaft, accessed by two doors at the surface, to allow mules to carry water containers up and down without obstructing each other. So when you visit the well do not just admire the fantastic feat of construction but also remember the events that caused it to be created at all.