At the end of the nineteenth century, Prince Alessandro Torlonia’s far-sighted and ambitious cultural project took shape for the constitution of a museum of ancient sculpture destined to welcome small groups of visitors to the imposing collection belonging to the family. In 1875, the year of its foundation, the museum – “a place sacred to the Muses” – housed a collection of 517 works which, by virtue of their magnificence, exemplarity and refinement, matched the prestige of the great museums of the time, first and foremost the Capitoline and the Vatican Museums. The collection was enlarged up until 1884, by which point there were 620 sculptures. The exhibition centre, located in Via della Lungara and adjacent to Porta Settimiana, was conceived according to a well-defined structure, which provided for the presence of galleries, divided into halls and aisles, and organised into compartments. The layout of the spaces reflected the desire to impose rigorous order onto the numerous marbles present, proposing a thematic division of the works, functional to the educational vocation of the museum. Particularly famous was the gallery of imperial portraits that triumphantly brought the exhibition itinerary to a close, with its eminent figures from the history of ancient Rome all standing side by side.