The obelisk is the same as the one that can be seen today in Villa Celimontana; it was originally erected in Heliopolis by Ramses II. Together the two obelisks were brought to Rome to adorn the temple of Isis (Iseum). It is made of red granite and is about 20 feet tall. Originally it might have been about 1 meter higher. The inscriptions contain phrases that indicate the kinship relation between the pharaoh and the Sun god ("Excellent son of the Sun god") and remember the works done in honor of the god.
No details are known about the transport of the twin obelisks to Rome. This obelisk, which is located in front of the Pantheon, was discovered lying near the church of S. Maria sopra Minerva, which had been erected on the ruins of the temple of Isis. After the discovery, towards the end of the 1300s, it was moved in front of the small church of S. Macuto.
Here it was arranged in a very rudimentary way, on four nuts that supported it and without any decoration. Rome in those years, following the absence of the popes who had moved to Avignon, was facing great poverty and its population had fallen to about 25,000 inhabitants.
At the time of pope Clement XI (1700-1721) various hypotheses were formulated in order to give the small obelisk a more suitable location: in the port of Ripetta, in Campo de' Fiori, in Piazza SS. Apostoli, in front of St. Mark's Palace or near the Arch of Constantine.
In 1711 it was erected in its present location on a pedestal decorated with a fountain with dolphins, adapting it to the 16th century fountain with masks by Giacomo della Porta.