Donated to the Florentine church of San Egidio by Tommaso Portinari, who from 1465 had been manager of the Medici family's commercial interests in Bruges.
The central panel is flanked by two wings depicting other members of the Portinari family and the family's patron saints, with a grisaille Annunciation on their reverse.
The left wing shows three kneeling members of the Portinari family, Tommaso Portinari and his two sons Antonio and Pigello. Above them stand Saint Anthony Abbot and Saint Thomas.
The right wing shows Tommaso Portinari's wife, Maria Baroncelli with her elder daughter Margherita, accompanied by Mary Magdalen and St Margaret.

Painted for the high altar of the Brotherhood of Corpus Domini in Urbino.
In the background, to the right, is a lively group made up of Federico da Montefeltro, Duke of Urbino with two of his courtiers and Caterino Zeno, the ambassador of the Shah of Persia. Just behind this group is a young woman carrying the young Guidobaldo in her arms.
The presence of Caterino Zeno indicates that the Holy Eucharist is a universal sacrament. Combined with the Flemish style of the work, the twin elements emphasise the cosmopolitan nature of Federico's court.
The picture was based on a fresco by Fra Angelico that Justus may have seen at San Marco in Florence, in which the disciples leave the table to kneel at Christ's feet. Despite this, the work shows how Justus's style remained purely Flemish.

Part of a series of famous men that Justus executed for Federico da Montefeltro's studiolo in his new palace in Gubbio.
After he had painted The Institution of the Eucharist he went on to make twenty-eight portraits of famous men for the studiolo. He was assisted by Pedro Berruguette, who painted a portrait of Federico and his son.
(Pedro also painted Federico's hands on Piero della Francesca's Montefeltro Altarpiece).

Part of Justus's work for Federico da Montefeltro's studiolo in his new palace in Gubbio.
Inscribed on the entablature behind the throne is I (?)ECLESIE CONFALONERIVS. This draws the viewer's attention to Federico's office as Standard Bearer (Commander in Chief) of the papal armies.
Music, one of the Seven Liberal Arts, is enthroned and points to an organ. The kneeling youth may be Costanzo Sforza (born 1447), whose imprese was a spray of laurel which is seen hanging behind him.

Part of Justus's work for Federico da Montefeltro's studiolo in his new palace in Gubbio.
Inscribed on the entablature behind the throne is DVX VRBINI MONTIS FERETRI AC (Duke of Urbino, [Count of] Montefeltro and ...).
The enthroned figure, pointing to a book, is Rhetoric, one of the Seven Liberal Arts.

Painted in glue size on linen.
The picture formed part of a large winged altarpiece of the Life of Christ. It was painted on a lightweight cloth support and rolled up for export to Italy, where it was recorded in the nineteenth century.
Like many such works, it has painted borders, which would have served as a guide to re-stretching the picture once it reached its destination.