The churchmen present at Pisa had enunciated…

The churchmen present at Pisa had enunciated the conciliarist theory that councils are superior to the pope, and had thereupon deposed both popes as heretical and schismatic.

They had then complicated the schism by electing a third claimant to the papacy, who had taken the name Alexander V, to be succeeded following his death eleven months later by the election, on May 25, 1410, of forty-year-old Baldassare Cossa, who had studied law and serves as an administrator in the Curia while endeavoring to end the schism; Cossa takes the reign title John XXIII; he had been ordained priest only one day earlier.

The Pisan claimants receive the support of most of Latin Christendom, but the schism continues.

John XXIII proclaims a crusade against Ladislaus and authorizes the sale of indulgences to finance it.