XII authorized the council as well. The council resolved that all three popes should abdicate and a new pope be elected. Flight from the Council of Constance In March, John escaped from Constance disguised as a postman. According to the Klingenberger Chronicle, written by a noble client of Frederick IV, Duke of Austria, John XXIII travelled down the Rhine to Schaffhausen in a boat, while Frederick accompanied him with a small band of men on horseback. There was a huge outcry in Constance when it was discovered that John had fled, and Sigismund was furious about this setback to his plans for ending the Schism. The King of the Romans issued orders to all the powers on the Upper Rhine and in Swabia stating that he had declared Frederick to be an outlaw and that his lands and possessions were forfeit. In due course this led to a great deal of political upheaval and many Austrian losses in the region, notably in Aargau to the Swiss Confederation. In the meantime, Antipope John XXIII and Frederick fled further downriver along the Rhine to the town of Freiburg im Breisgau, which recognised the duke of Austria as its lord. There Sigismund's lieutenant Ludwig III, Elector Palatine caught up with them. He convinced Frederick that he stood to lose too much by harbouring the fugitive pope, and the Austrian duke agreed to give himself and John up and return to Constance. Deposition During his absence John was deposed by the council, and upon his return he was tried for heresy, simony, schism and immorality, and found guilty on all counts. The 18th century historian Edward Gibbon wrote, "The more scandalous charges were suppressed; the vicar of Christ was accused only of piracy, rape, sodomy, murder and incest." John was given over to Ludwig III, Elector Palatine, who imprisoned him for several months in Heidelberg and Mannheim. The last remaining claimant in Avignon, Benedict XIII, refused to resign and was excommunicated. Martin V was elected as new pope in 1417. Death and burial Cossa was again imprisoned in Germany. He was freed in 1418 after a heavy ransom was paid by the Medici. He went to Florence, where he submitted to Martin V, who made him Cardinal Bishop of Frascati. Cossa died only a few months later. The Medici oversaw the construction of his magnificent tomb by Donatello and Michelozzo in the Battistero di