FILLASTRE, GUILLAUME. - Born at La Suze (Maine) c. 1348. He studied law, was a priest and a renowned preacher. Dean of Reims in 1392. He revealed his personality at the Synod of Paris in 1406, where he defended the antipope BENEDICT XIII against the representatives of the king and the university, arguing that princes have no right to judge matters of the Church and that general councils are not above the Pope.
At the time of the Council of Pisa (1409), he separated from Benedict XIII, together with D’Ailly, and became one of the promoters of the other antipope JOHN XXIII, who created him a cardinal on 6 June 1411. At the Council of Constance, in which he played a leading part, he opposed John XXIII and, contrary to the vigorous opinions he had expressed at the Paris Synod of 1406, he upheld the superiority of the council over the Pope and succeeded in having the five famous articles approved by the assembly after reconciling the cardinals with the Emperor Sigismund. He did not take part in the trial of Hus and Petit because of illness. He returned to the Council in 1417 and was entrusted with obtaining the resignation of the deposed Benedict XIII; he carried out this task, and at the 37th session on 26 July 1417 he himself read the conciliar sentence of deposition against the antipope Benedict. He played an active part in the conclave that elected MARTIN V, who entrusted him with various diplomatic missions in France and appointed him archpriest of St John Lateran. Died at Rome on 6 Nov. 1428.
F.’s fame, apart from his ecclesiastical politics, is linked to the works he left in manuscript. His sermons are of the greatest importance. He wrote on theology and law, on science and geography, and drew up a very detailed account of the Council of Constance. Although various accusations were levelled against him, such as his volte-face against John XXIII who had made him a cardinal and his repudiation of the opinions, unassailable from the theological point of view, which he had expressed at the Paris Synod, he is nevertheless excused by his good intentions in seeking a way out to end the schism.