F. Haskell and N. Penny, Taste and the Antique - The Lure of Classical Sculpture 1500-1900, New Haven and London, 1981, pp.178-179, figs. 91 and 92.
The antique originals were both found by Monsignor Furietti in the excavations at Hadrian's Villa in December 1736, where they would have stood in the domed hall of the small palace.
The Furietti Centaurs were much in demand, and it is said that Pope Benedict XIV was so annoyed with Furietti for refusing to give the pair to the Capitoline Museum in Rome that he passed him over for a cardinal's hat. However, in 1765 the centaurs were finally bought from Furietti's heirs by Pope Clement XIII, who placed them in the Capitoline Museum, where they are to this day.
The Greek inscriptions on the side of the plinths name the centaurs as being by Aristoteas and Papias of Aphrodisias.