The oldest building of the Pantheon, the temple of all the gods, was erected in 27 BC by Marcus Agrippa. Between 118-128, the temple was extensively rebuilt under Emperor Hadrian, and assumed the forms it retains to this day.
The inscription on the architrave reads, "Marcus Agrippa, son of Lucius, Consul the Third, did". It was left by Hadrian, who did not put his name on any of the monuments. The reconstruction, carried out according to the design of Apollodorus of Damascus, considerably modified the original appearance of the building. An extensive portico formed by eight columns of grey granite has been preserved. Two columns of red granite each stand behind the first, third, sixth and eighth columns, forming three aisles. The tympanum was once decorated with a bronze eagle with a crown. The ceiling of the portico was also decorated with bronze, removed at the behest of Pope Urban VIII Barberini, hence the famous expression: "What the barbarians didn't do, the Barberini did". The dome that crowns the building, a true masterpiece of engineering, was created entirely on wooden formwork and is the widest dome ever built.
Inside, the building is flanked on each side by six niches, each framed by two columns. The dome is decorated with five rows of diminishing upward caissons, except for the last row around a circular opening, the so-called "eye of the Pantheon", 9 metres in diameter, through which a stream of light pours inwards.
The Pantheon is now the national mausoleum. The first to express his desire to be buried here was the painter Raphael. Later, other famous personalities were buried here, including members of the Savoy royal dynasty.
