in 1409, was named after the town of Pisa, Italy, where the (Pisan) council had elected antipope Alexander V as a third claimant. To end the schism, in May 1415, the Council of Constance deposed antipope John XXIII of the Pisan line. Pope Gregory XII of the Roman line resigned in July 1415. In 1417, the council also formally deposed antipope Benedict XIII of Avignon, but he adamantly refused to resign. Afterwards, Pope Martin V was elected and was accepted everywhere except in the small and rapidly diminishing area of influence of Benedict XIII. List of historical antipopes The following table gives the names of the antipopes included in the list of popes and antipopes in the Annuario Pontificio, with the addition of the names of Natalius (in spite of doubts about his historicity) and Antipope Clement VIII (whose following was insignificant). An asterisk marks those who were included in the conventional numbering of later popes who took the same name. More commonly, the antipope is ignored in later papal regnal numbers; for example, there was an Antipope John XXIII, but the new Pope John elected in 1958 was also called John XXIII. For the additional confusion regarding popes named John, see Pope John numbering. The list of popes and antipopes in the Annuario Pontificio attaches the following note to the name of Pope Leo VIII (963–965): At this point, as again in the mid-11th century, we come across elections in which problems of harmonising historical criteria and those of theology and canon law make it impossible to decide clearly which side possessed the legitimacy whose factual existence guarantees the unbroken lawful succession of the successors of Saint Peter. The uncertainty that in some cases results has made it advisable to abandon the assignation of successive numbers in the list of the popes. Thus, because of the obscurities about mid-11th-century canon law and the historical facts, the Annuario Pontificio lists Sylvester III as a pope, without thereby expressing a judgement on his legitimacy. The Catholic Encyclopedia places him in its List of Popes, but with the annotation: "Considered by some to be an antipope". Other sources classify him as an antipope. As Celestine II resigned before being consecrated and enthroned in order to avoid a schism, Oxford's A Dictionary of Popes (2010) says he "...is classified, unfairly, as an antipope," a position historian Salvador Miranda also shares. Those with asterisks