Answer: When Angelo Giuseppe Roncalli was elected pope in 1958, his choice of the name John XXIII immediately caught the attention of historians and canon lawyers, because the title had already been used by a claimant elected at the Council of Pisa in 1410. That earlier John XXIII had been the successor to Alexander V and part of the third papal line created during the Western Schism. Roncalli’s decision was not an oversight but a deliberate historical clarification. By stating that he was following the line of “twenty‑two Johns of indisputable legitimacy,” he signaled that the Pisan John XXIII was not to be counted among the true popes. In doing so, he affirmed the Church’s long‑developing view that the Pisan line represented a temporary and ultimately illegitimate attempt to resolve the Schism. His choice effectively reinterpreted the numbering of popes named John and quietly reinforced the distinction between recognized pontiffs and those later classified as antipopes, bringing a measure of order to a period of profound ecclesiastical confusion.