The painting depicts Sebastiano Serlio (1475, Bologna – 1554/1555, Fontainebleau), a prominent representative of the late Italian Renaissance and the Fontainebleau school of Mannerism. He was an architect, painter, scenographer, and author of the treatise "Seven Books on Architecture". His portrait belongs to the "uomini illustri" type, that is, portraits of famous people. After moving to Rome in 1515, Sebastiano Serlio became a student of Baldassare Peruzzi and a follower of Donato Bramante and Raphael Santi. Between 1527 and 1541, he worked in Venice. Later the master moved to France at the invitation of Francis I, where he was appointed a chief architect. He became famous for his theoretical treatises, which contributed to the spreading of Classicism in European countries to the north of the Alps. The painting in the collection of Borys Voznytskyi Lviv National Art Gallery is thought to be a replica of "Portrait of Sebastiano Serlio" (1570s–1580s, Martin von Wagner Museum, Würzburg) by Bartolomeo Passarotti (1529–1592), a prominent Bolognese painter of the late 16th century and a compatriot of the architect. The uniqueness of the canvas from the Gallery's collection, as well as its prototype, is its association with the Renaissance portrait tradition. This is indicated by the bust depiction, three-quarter turn, attention to individual features, and characterisation of a person as an active and thinking one, and notably represented through external details, such as a compass in his hand. Contrasting lighting and rich and restrained colouring facilitate the representation of the essence. Facial expression, figure turning, and hand gestures complement the image with truthfulness and expression. The peculiarity of the portrait is its dialogic nature and address to the viewer. The belonging of the portrait to the "uomini illustri" type is indicated by the inscription "Bastianino Serglio", typical for such works. The painting from the Gallery's collection and the prototype from Würzburg differ only in the signature location. It allows us to assume that it comes directly from Bartolomeo Passarotti's workshop, where his two grandsons and three sons worked alongside the prominent artist.