Concentrating on Roman antiquities after 1897 (the year he was awarded a Craven fellowship), he next published his first article ('The true site of Lake Regillus', 1898), gained an Oxford degree of DLitt (1905) and won the Conington Prize for classical learning (1906).

(Also, in 1890, four years after the Staines brewery's privatisation, Ashby's father had settled in Rome, exploring the Campagna and becoming friends with Rodolfo Lanciani.)

Ashby enrolled in January 1902 as the first student of the British School at Rome, under its first director Gordon McNeil Rushforth, and was the same year appointed its honorary librarian and elected as a fellow of the Society of Antiquaries.

Trying to make the British School at Rome a focus for archaeological research in the western Mediterranean, Ashby appointed as associate student of the BSR Duncan Mackenzie, who had just worked with Arthur Evans at Knossos.

With the support of the British ambassador Sir Rennell Rodd, the BSR decided in 1912 to relocate a new, larger, permanent building in the Valle Giulia, designed by Lutyens, and to expand into not only archaeology but also art and architecture.

Ashby felt this appropriate to his Quaker leanings and, though it drew criticism, he was still asked to return to Rome and the BSR, and was mentioned in dispatches for his bravery in his ambulance work on the Asiago plateau.

Excavation in Italy, in the post-Risorgimento period of the 1910s, was limited to Italians and disallowed to foreigners, leading to their concentration on topographical and museum studies.

[8] Indeed, Ashby grew into a master of Rome's urban topography, working from both classical and early modern literature and prints, and drawing on (among other things) Antonio Labacco's 16th century architectural drawings, Eufrosino della Volpaia's 1547 map of the Campagna, Étienne du Pérac's 1581 topographical studies, Giovanni Battista de'Cavalieri's "Antiquae statuae urbis Romae", and the art collections at Windsor Castle, the Sir John Soane Museum, and Eton College.