 In 1696 he was named an Assistant at the Pontifical Throne; in Rome his knowledge of English affairs made him so useful that his repeated petitions for leave to return to his vicariate were refused.In 1704 Ellis resigned the vicariate, and in 1708 was made the Bishop of Segni by Pope Clement XI, being enthroned on 28 October.His first care was to rebuild the ruined Monastery of Santa Chiara and open it as a diocesan seminary.