Early medieval sources record the presence of these peacocks in the area around Hadrian's Mausoleum (117-138 A.D.), known today as Castel Sant'Angelo. These gilded bronze birds were for a long time part of the decoration of the great cloister in front of the old basilica of St Peter, ornamenting the so-called Cantaro.
It was a fountain in which pilgrims could wash themselves formed of the great bronze pine cone which now forms the focal point of the Courtyard of the Pinecone in the Vatican Museums. In 1608, during the building of the new basilica of St Peter, the peacocks were also moved to the Courtyard of the Pinecone, and later brought here to where they are now kept to ensure their preservation. The peacocks are notable for their extremely fine workmanship which can be seen in the realistic details and the refined representation of their plumage. These characteristics, together with the symbolism of the peacock as representing immortality, reinforce the theory that these birds were indeed part of the original decoration of Hadrian's Mausoleum.