of Aviz. In January 1444, Peter of Coimbra endowed a fund for a yearly mass to be said in Ferdinand's honor at his chapel in Batalha. Henry the Navigator commissioned a triptych of the life and sufferings of Ferdinand, painted by João Áfonso, to be set up in his own (Henry's) chapel. Some modern authors believe the celebrated Saint Vincent Panels by Nuno Gonçalves were commissioned by Peter of Coimbra as a funerary homage to Ferdinand the Holy Prince. The religious iconography of Ferdinand the Holy Prince usually portrays him as a miserable prisoner, hungry, bearded, disheveled in a black cloak and hood, his feet in leg irons and chains held in his hands. He also sometimes holds a hoe, for his labors in the palace gardens in Fez. Later on, Ferdinand was sometimes depicted in the armor of an imperial warrior. The promotion of the saintly cult, in particular the narrative twist that Ferdinand had "volunteered" for martyrdom rather than allow Ceuta to be surrendered, was principally due to Henry the Navigator and may have been motivated by an attempt to deflect responsibility for his death away from himself. In the 1450s, Henry commissioned Frei João Álvares to set down the details of Ferdinand's life and captivity. Finished sometime before 1460, and first published in 1527, the Álvares chronicle is the principal source of the life and travails of Ferdinand. Although originally intended as a piece of Christian hagiography to supplement the cult of the "Holy Prince" and the Henrican interpretation, the Álvares chronicle did not flatter Henry's leadership nor absolve him of responsibility for Ferdinand's fate. He makes it reasonably clear that Ferdinand did not seek out a martyr's fate, but had it imposed on him by the delays and machinations back in Portugal. At several points, Álvares surreptitiously points an accusatory finger at Ferdinand's brothers via speeches from the mouth of Ferdinand, his companions and his captors. Another hagiography, the Martirium pariter et gesta, written by an unknown author, appeared around the same time or shortly after. Some have speculated the Martirium might have been written by Pero Vasques, the ransomed chaplain, although others believe it was a largely derivative piece, hurriedly written by someone else, commissioned by Isabella of Burgundy to support the campaign in Rome to promote Ferdinand to sainthood. Ferdinand's sister Isabella of Portugal, Duchess of Burgundy, endowed a mass to be said in