In 1309, the Pope decided to leave the dirty, smelly, disease ridden city of Rome, for the much more pleasant environs of Avignon in France. Seven Popes in turn resided there. But in 1377, Gregory XI returned to Rome, where he almost immediately proved the wisdom of his predecessors by succumbing to the perils of the deadly city.

In April 1378, the cardinals met in Rome to elect a new Pope. The Roman mob made it abundantly clear what would happen to them if they did not elect an Italian as Pope. The conclave obliged and duly elected an Italian as Pope Urban VI. The cardinals then desperately flew from Rome as fast as their gilded carriages would allow. But as soon as they were safely clear they repudiated Urban VI, claiming they had been intimidated. The Holy Spirit really wanted Count Robert of Geneva to be Pope. He took the name Clement VII and dashed off to safety in Avignon.

Urban VI was not impressed and excommunicated the upstart Clement VII, who was quick to return the favour. Europe then proceeded to split down the middle. France and her allies supported Clement in Avignon, while the Holy Roman Emperor and his allies supported Urban in Rome.

There was a chance to resolve the issue in 1389 when Urban died. But the Italian cardinals didn’t wait for their French counterparts and elected Boniface IX, whom Clement in Avignon immediately excommunicated. Boniface returned the favour.

The reverse situation occurred in 1394, when Clement in Avignon died. This time it was the French cardinals who had the upper hand and elected Benedict XIII as the new Avignon Pope, who was then excommunicated by Boniface. Benedict returned the favour.

Boniface in Rome was succeeded by Innocent VII and then Gregory XII. Benedict in Avignon and Gregory in Rome then decided to resolve the issue by calling a council in Pisa. However, at the last minute both Popes backed out. The Council of Pisa went ahead. It deposed both Popes and elected Alexander V as the one true Pope. Despite being called by them, neither Benedict nor Gregory agreed with its decision and both refused to step aside. So there were now three Popes, one for each tier of the triple crown. Excommunications flowed freely.

The schism was eventually ended in 1414 by the Council of Constance, where all existing Popes were forced to stand down and Martin V was elected as the new Pope. However, in order to depose the Popes, Constance asserted that a council of the Church was its supreme authority, not the Pope. The Popes have made it very clear that that part of its work is invalid.

This would all make a jolly good film.