The extensive research on the artistic work of the Italian painters Giuseppe Trono (Turin, 1739 — Lisbon, 1810) and Bernardino Gagliardini (Vocca, 1757 — Lisbon, 1833) in Lisbon, focusing into the portrait painting activity during the reign of the queen Mary I, comes to confi rm the artistic collaboration between Trono, the leading portrait painter of the royal family since 1784, and Gagliardini or “Throno pequeno” (Machado, 1823), so-called because of his main activity into the production of miniatures. The work of both painters plays a considerable role in understanding the Portuguese artistic context and its implementation, pursued by the queen Mary I.