As dealer he most notably sold Caravaggio's The Death of the Virgin to Vincenzo Gonzaga, Duke of Mantua for 280 scudi in 1607; a transaction proposed to the Duke by Peter Paul Rubens and brokered by Giovanni Magno.
Henry Mancini | Giulio Romano | Giulio Tremonti | Roberto Mancini | Giulio Andreotti | Giulio Einaudi | Giulio Angioni | Giulio Natta | Giulio Douhet | Giulio Caccini | Giulio Belli | Antonio Mancini | Laura Mancini | Hortense Mancini | Giulio Ricordi | Giulio Paolini | Giulio Clovio | Giulio Benso | Giulio Bartolocci | Alberto Mancini | Monica Mancini | Marie Anne Mancini | Mancini | Giulio Roma | Giulio Questi | Giulio Petroni | Giulio Parigi | Giulio de' Medici (d. 1600) | Giulio de' Medici | Giulio Alberoni |
Giulio Mancini commented in his writings that Viola was well respected for his landscape canvases, which were annotated as present in the collections of Cardinal Pietro Aldobrandini, Giustiniani, Cardinal Mazarin, and the Pamphilj.