Carlo I Malatesta

Avignonese "antipope" Benedict XIII has resisted the pressure on him to abdicate, arguing that abdication is uncanonical.

Pointing out that he is the only surviving cardinal from before the Great Schism, Benedict concludes that his vote is the only one that is certainly valid, and he would, of course, choose himself.

The obstructive tactics of Benedict and the Roman claimant, Gregory XII, cause the cardinals of Rome and Avignon to despair of getting any cooperation from them toward unity.

Abandoning both, the cardinals summon the Council of Pisa in 1409, a general assembly of the Roman Catholic Church, recognized by neither claimant.

Ladislaus invades Tuscany in 1409, capturing Cortona and …

…the island of Elba from Iacopo II Appiani.

Florence hires the condottiere Braccio da Montone, who defeats Ladislaus, and he is forced to retreat.

Ladislaus has not abandoned his aims in northern Italy, however, and takes advantage of the presence of Pope Gregory XII in Gaeta.

The Republics of Siena and Florence and the powerful cardinal Baldassarre Cossa, fearing the aims of Ladislaus, ally against him.

Antipope Alexander V excommunicates him, and calls Louis II of Anjou back to Italy to conquer Naples.

Louis arrives in late July 1409 with fifteen hundred cavalry and is invested with the Neapolitan crown.

The allies' troops, under Muzio Attendolo, Braccio da Montone and other condottieri, invade the Papal lands under Ladislaus' control and move to Rome; Orsini, left by Ladislaus to protect the city, defects to them with two thousand men.

However, the allies capture only the Vatican and the Trastevere quarter.

Cardinal Cossa and Louis leave the siege to their condottieri, and move to northern Italy and Provence in search of further support.

Ladislaus has taken advantage of an anti-French revolt in Genoa to gain the support of this city in 1410.

Rome falls on January 2, and the allies do not score any other notable results.

Louis's fleet, carrying new troops from Provence, is intercepted on May 16 or 17 and partly destroyed off the Tuscan coast, with the loss of six thousand men and Louis's treasure (for a value of six hundred thousand ducats), which falls into the hands of Ladislaus.

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.

The slow pace of the allied army leads the Florentines and Sienese to accept peace with Ladislaus, which he buys by renouncing some of his Tuscan conquests.

Louis continues the struggle: his army, led by Muzio Attendolo, crushes the Neapolitan army at Roccasecca on May 19, 1411.

He is unable to exploit this success, as he cannot breach the defensive line that Ladislaus has set up at San Germano.

Louis soon returns to Rome and Provence, where he will die six years later.

The situation in Italy turns more favorable to Ladislaus in 1412: his condottiere Carlo I Malatesta occupies part of the March of Ancona, and, above all, Muzio Attendolo joins Ladislaus.

A peace is eventually signed on June 14, 1412, by which the Antipope pays seventy-five thousand florins, invests Ladislaus with the Neapolitan crown and names him as Gonfalonier of the Church.

Ladislaus promises in turn to abandon the cause of Gregory XII, who is ousted from Gaeta and moved to Rimini.

The peace, however, has been only a means to gain time for both John XXIII, who does not want to pay the seventy-five thousand florins, and Ladislaus, who fears intervention in Italy by Sigismund of Hungary.