Tomb of Antipope John XXIII - Commissioning

Commissioning

The commissioning of Cossa's tomb monument was negotiated for about a decade following Cossa's death. Cossa's last will and testament—written on his death bed on December 22, 1419—made several of the customary Florentine civic bequests, acts of charity, and traditional ecclesiastical courtesies, but the bulk of his estate was left to his nephews Michele and Giovanni. The bequests to his nephews took priority, and his estate remained disputed by various creditors while the tomb was being completed.

Cossa designated four prominent Florentines as his executors: Bartolommeo di Taldo Valori, Niccolò da Uzzano, Giovanni di Bicci de' Medici, and Vieri Guadagni, allowing any two of the executors to act on behalf of all four, as Valori and Medici appear to have done. Valori died on September 2, 1427, by which time Guadagni was also deceased and Uzzano had long lost interest, leaving the remaining work of commissioning entirely to Giovanni, or—more likely—Cosimo de' Medici.

The executors claimed that Cossa had revealed his desire for burial in the Baptistry to them but had been too modest to request it in his will. Most later scholars accept this testimony of the executors, attributing Cossa with "tact—and tactics", although at least one has postulated that the executors chose the site of the Baptistry against Cossa's wishes.

Documentary records indicate that, on January 9, 1421, Palla Strozzi, on behalf of the Arte di Calimala, the guild who were responsible for the upkeep of the Baptistry, authorized a "breve et honestissima" ("small and inconspicuous") monument in the Baptistry, but not the chapel requested by Cossa's will; present scholarship accepts Strozzi's assertion that burial within the Baptistry was a considerable honor, perhaps beyond the status of Cossa. After this meeting, there are no extant records from the Calimala regarding the tomb as the bulk of documents from the 1420s have been lost, although the notes of Senatore Carlo Strozzi, who went through the records, are extant.

The Calimala's acquiescence is traditionally explained by Cossa's donation of the relic of the right index finger of John the Baptist (and 200 florins for an appropriate reliquary) to the Baptistry. With this finger John was believed to have pointed to Jesus, saying "Ecce Agnus Dei" ("Behold the lamb of God") in John 1:29. The long and complicated history of the relic would only have increased the legendary status of the finger: Philotheus Kokkinos, Patriarch of Constantinople presented it in 1363 to Pope Urban V, who passed it to his successors Gregory XI and Urban VI, who was dispossessed of it during the siege of Nocera, after which John XXIII bought it for 800 florins and wore it on his person before hiding it in the monastery of Santa Maria degli Angeli.