Between 1473 and 1475 an artist named "Giusto da Guanto" (Justus of Ghent) is documented as the painter of the Communion of the Apostles altarpiece in Urbino. This man is clearly identical with a Flemish master named Joos van Wassenhove, active at Antwerp in 1460 and recorded at Ghent from 1464 to 1469. A Flemish document of 1475 states both that he was an associate of Hugo van der Goes and that he had gone to Rome some time previously.
A handful of pictures such as the Adoration of the Magi (ca. 14605; Metropolitan Museum, New York) have been attributed to Justus from the period before he left the Netherlands, by stylistic comparison with his only documented work, the Communion altarpiece. The most substantial of these is the Mount Calvary triptych in St-Bavon Cathedral, Ghent. Like the Urbino painting, it reveals points of contact with northern Netherlandish art, especially that of Dieric Bouts. The Communion of the Apostles (Galleria Nazionale delle Marche, Urbino) was produced for a confraternity (for the church of St Agatha in Urbino) under Montefeltro patronage (Federico da Montefeltro is actually portrayed in the painting). Joos is usually identified with the anonymous painter of a large group of pictures in a Netherlandish style executed for the Urbino court. These consist of 28 portraits of Famous Men (philosophers, writers, and poets) which were probably painted ca. 14736 for the ducal study in Urbino. Four fragments from a series of The Seven Liberal Arts. These, together with a portrait of Federico da Montefeltro Attending a Lecture, were also painted ca. 147680 for a similar study in Gubbio. The Famous Men group is divided between Paris (Louvre) and Urbino (Galleria Nazionale delle Marche) and the Liberal Arts between London (National Gallery and Hampton Court Palace), and (until their destruction in 1945) Berlin. It has often been suggested that Pedro Berruguete assisted Joos with both schemes. This seems probable, although it is clear that the Spaniard could only have played a very subordinate role in the work.
Joos is the only Flemish painter of the 15th century some of whose surviving works are actually known to have been produced in Italy. These paintings reveal his steadily increasing mastery both in the handling of illusionistic perspective and in the representation of Italianate subject matter. For these reasons he is a highly interesting forerunner of the rapprochement between Flemish and Italian art which took place during the early 16th century.