[8] It is then possible that as Portica was meant the succession of house porches, a common feature in Roman medieval architecture, which allowed the pilgrims to reach Saint Peter from Ponte Sant'Angelo without walking on open air.

Assuming that the Portica existed, it should have collapsed during this period, and was never restored, since the popes understood well that any covered passage could have been a precious shelter for enemies trying to assault the castle and to reach the bridge.

[5] In the late 15th century, after the beginning of the Renaissance, two other roads leading to Saint Peter from Ponte Sant'Angelo were built: Borgo Sant'Angelo, also known as Via Sistina after Pope Sixtus IV (r. 1471–84), running just south of the Passetto (the covered passage linking Vatican with the Castle),[14] and Borgo Nuovo, also known as Via Alessandrina, after Pope Alexander VI Borgia (r. 1492–1503), who erected it.

[20] Another important building was a palazzetto at n. 121–22 erected by Pope Gregory XIII (r. 1572–85) as a residence for the staff of the Hospital of Santo Spirito in Sassia; it had a rusticated ground floor, windows on the piano nobile with alternate triangular and curved tympanums and an arched attic.

[22] The house between Borgo Vecchio and the southwest corner of the piazza hosted in the 15th century two deposed queens: Catherine of Bosnia, which lived there in 1477–78,[23] and Charlotte of Cyprus.

[26] Further west, on the north side, the Cybo, a noble family which reached the papal seat with Pope Innocent VIII (r. 1484–92), erected their houses at the end of the 15th century.

[28] The last buildings on the south side of the road before its end on piazza Rusticucci were the church of San Lorenzo in Piscibus ("St. Lawrence in the fish market", still existing, although stripped of its baroque superstructures and decorations and hidden in the yard of the southern propylaea of Saint Peter's Square)[29][30] and the Palazzo Alicorni, a severe Renaissance palace demolished in 1931 to delimit the border of Vatican City after the signing of the Lateran treaties.

[27] Around 1660, during the reign of Pope Alexander VII (r. 1655–67), after the construction of the colonnade of Bernini, the first block of the spina between Borgo Vecchio and Borgo Nuovo towards St. Peter, named isola del Priorato after the building hosting the Priory of the Knights of Rhodes,[31] was pulled down in order to create a space–the Piazza Rusticucci–which allowed the full view of Saint Peter's dome, hidden by the nave of Maderno.

At the beginning of the 19th century, when Rome was part of the First French Empire, the prefect of the city, de Tournon, started the demolition of the spina.

[34] They have the same late neoclassical style as the Manifattura dei Tabacchi ("Tobaccos factory") in piazza Mastai in Trastevere,[34] erected by Antonio Sarti a few years later.

[34] In 1867, a bomb placed in the Palazzo Serristori (at that time a barrack of the pontifical army) in Borgo Vecchio killed many zuavi (papal soldiers).

[16] Between 1934 and 1936, when the project of Via della Conciliazione was developed, the architects Marcello Piacentini and Attilio Spaccarelli chose to give to the new road the alignment of Borgo Vecchio, and not of the nearby Borgo Nuovo,[38] which had been aligned between the now disappeared tower of Alexander VI near the Ponte Sant'Angelo and the bronze gate of the Vatican, and had a slope of 6 degrees with respect to the old Saint Peter.