On the death of Liberius (366) a considerable party nominated Damasus successor; but the irreconcilables of the party of Liberius refused to pardon his trimming, and set up against him another deacon, Ursinus.
But he was reproached for accepting it by the extreme republicans and irreconcilables.
Twenty thousand Carlist volunteers laid down their arms at Vergara; only the irreconcilables led by Cabrera held out for a while in the central provinces of Spain.
The first session at Florence and the seventeenth of the union council took place on the 26th of February 1439; there ensued long debates and negotiations on the filioque, in which Markos Eugenikos, archbishop of Ephesus, spoke for the irreconcilables; but the Greeks under the leadership of Bessarion, archbishop of Nicaea, and Isidor, metropolitan of Kiev, at length made a declaration on the filioque (4th of June), to which all save Markos Eugenikos subscribed.
Dividing what the irreconcilables of the Hildebrandine party considered as an indissoluble whole, they made a sharp distinction between the property of the Church and the Church itself, between the political and territorial power of the bishops and their religious authority, and between the feudal investiture which confers lands and jurisdiction and the spiritual investiture which confers ecclesiastical rights.