From Gregory, the powerful Count of Tusculum, father of Popes Benedict VIII and John XIX, Nilus obtained the site, which had been a Roman villa, where among the ruins there remained a low edifice of opus quadratum that had been a sepulchral monument but had been converted to a Christian oratory in the fourth century. Its iron window grates gave the site the name, first of Cryptoferrata then of Grottaferrata, commemorated in the coat-of-arms of the commune. From the site, a Roman bronze of a man and a cow attracted the antiquarian attention of Frederick II, Holy Roman Emperor, who had the group removed to Lucera.[3]