The Roman Cardinal Whose 1417 Election at Constance Finally Ended the Forty-Year Western Schism

Oddone Colonna was 49 years old when the Council of Constance elected him pope on 11 November 1417. He had been a Roman cardinal since 1405 — an appointment from the Roman-line pope Innocent VII — and had been part of the diplomatic delegation that the Council had used to negotiate with each of the three rival papal courts through the substantial preceding three years.

The Council had inherited the substantial three-pope situation that the failed Council of Pisa of 1409 had produced. Constance had been convened in November 1414 by the Holy Roman Emperor Sigismund of Luxembourg with the specific objective of ending the Western Schism that had divided Catholic Europe for thirty-six years.

The Council achieved this in stages. The Pisan claimant John XXIII was deposed in May 1415 on charges of personal misconduct and procedural-electoral irregularity. The Roman claimant Gregory XII voluntarily abdicated in July 1415, on the condition that the Council would formally recognise the Roman-line papal succession as the substantively legitimate one. The Avignon claimant Benedict XIII refused to abdicate or accept deposition; the Council substantively deposed him in absentia in July 1417 and substantively left him as a -isolated pretender in his Aragonese-Catalan refuge at Peñíscola until his death in 1423.

The November 1417 election conclave was a novel construction. The Council added 30 non-cardinal delegates (six per ‘nation’ — Italian, French, German, English, Spanish) to the 23 surviving cardinals. The enlarged 53-member conclave substantively elected Colonna unanimously on the third ballot.

He took the regnal name Martin V in honour of Saint Martin of Tours (the 11 November election day was Saint Martin’s feast day). He substantively reigned from 1417 to 1431; he substantively returned the papal court to Rome in 1420; he substantively was the first -undisputed pope since 1378 and substantively the restorer of Roman papal continuity that has substantively continued without further substantively schism through the subsequent six centuries.