So…how is it possible that this age old problem came to an abrupt resolution? There is no definite answer, because no clear documentation exists. However, reasonably, the design of Nicola Salvi, is probably the reason why.
Salvi, Vanvitelli and Galilei all took part in the competition for the façade of St. John Lateran, announced at the same time as the competition for the Trevi. Milizia wrote that, “The adjudication for St. John was carried out by academicians from Saint Luke’s in the hall of the Quirinale. In his personal memoirs, Vanvitelli says that his designs were selected as well as one by Salvi; but the Pope was informed that the votes had been equal and that, as Galilei was a national, his design deserved preference, so the Trevi fountain was given to Salvi and the port of Ancona to him [Galilei]”. Vanvitelli’s own words stated his designs were best, but Galilei was chosen because he was a countryman of the Pope, and because the Trevi was given to Salvi. So, the decisions were probably a “Like sticking to like” kind of decision by the panel of judges for the St. John competition.
It is rather absurd to think that Galilei only won because he was from the same place as the Pope. It was actually because the judges were looking for the design that could best fit the requirements for the structure that Borromini left unfinished. According to the opinion of the people, the only design that would work for the façade was something that was close to the spirit and design of the architect Borromini. So, this then, is the real motive behind Clement XII who preferred Galilei’s design, even when the other designs may have been more pleasing.
The question then becomes, did the same thing happen with the Trevi Fountain? Did the panel prefer Vanvitell’s ideas, but chose Salvi’s design because it was closer to the design and spirit of Gian Lorenzo Bernini? Therefore, even after the deaths of the two great architects, their direction and design lived on through their disciples. Ironically, these two were rivals when they were living, and would remain rivals always, as one would create something, then the other would need to be in the spotlight as well!