The city of Rome, a unique case in the world, has been inhabited continuously for over 2700 years, and its monuments have been reused several times over the centuries and adapted to different situations.
The oldest example are the Egyptian obelisks, brought to Rome during the Empire, knocked down by invasions and earthquakes, recovered and raised in the 1500s and 1600s to embellish the squares.
The San Giovanni obelisk has had many lives in its 3500 years of age.
Starting from the time of Constantine, statues and columns from previous buildings began to be recovered to embellish the monuments of the time.
For example in 315 AD, when the Senate decided to erect a Triumphal Arch in honour of Emperor Constantine, statues and bas-reliefs were recovered from buildings of the time of Trajan and Hadrian. So already 200 years old.
To build their churches, the first Christians took columns and marbles from abandoned imperial buildings.
From 392 AD, with the decrees of Theodosius, Christianity became mandatory and the possibility of destroying pagan temples or transforming them into Christian churches was sanctioned. Although until 750 the Church did not have civil and judicial power, which remained the right of the state.
Since the early Middle Ages, many fortifications were built on tombs and ruins of the ancient city, for example the Caetani built their fortress using the Tomb of Cecilia Metella, in via Appia.
The Knights of Rhodes, then of Malta, built their Palace in the Roman Forum on the remains of Trajan’s Markets.
Meanwhile, the Church of San Lorenzo in Miranda in the Roman Forum was built inside the Temple of Antoninus and Faustina, keeping the external colonnade.
Castel Sant’Angelo was built on Hadrian’s Mausoleum.
A sensational example of reuse of an ancient building is the Teatro di Marcello. Around the year 15 before Christ, Julius Caesar had a large theatre built to dedicate to his nephew Marcello.
In Rome on that date there was only the Pompeo Theatre, from 55 BC.
The Teatro di Marcello had 15,000 seats and three rows of arches, and was used until 420 AD, then was abandoned for centuries.
Around 1350 the Savelli built their fortress on the ruins of this theatre, from which marble and statues had been stolen. The fortress became a palace purchased in the eighteenth century by the Orsini.
From 1926 to 1932, when the Via del Mare was opened and the surrounding neighbourhood demolished, the theatre was restored, the earth that covered the base was removed, the shops were removed and some arches of the second level were rebuilt.