The two thirds majority rule for the election of a new pope was set in 1179 ( Alexander III’s Licet de vitanda constitution)
and did away with a number of setbacks but also had some side effects
such as lengthy holiday periods and a great deal of intervention from
imperial powers, which in some cases ended up making cardinals hostages
of their own plans. Even Roman Catholics found a way to express the absolute need to see a Pope installed in record time: if the Church was meant to be led regimen unius persona¸ those who had to ensure this were under a lot of pressure to do so.
When Innocence III died in 1216, the citizens of Perugia adopted the system used in other civil procedures to speed up the process: they forced cardinals to elect the Pope through a forced seclusion; in 1241, when Gregory IX died, the Roman senate, headed by Matteo Rosso Orsini, locked the ten cardinal in charge of electing the Pope in the ramshackle palace of the Septizodium, erected by Emperor Septimius Severus on the Platine Hill, because they could not agree on the next successor.
The cardinals, who were almost tortured by the violent guards had to find a way to overcome the hesitations of Frederick II who wanted a Pope who would favour the unification of the Imperial and Sicilian Kingdoms. This was the first ever Conclave, but there was absolutely no willingness to accept or formalise this papal election method.
When Clement V died in 1268, after 18 months of deliberation, the seventeen cardinal electors were locked inside the Papal Palace of Viterbo, their physical strength tested to the limit: all they got was bread and water and the city’s magistrates even had the roof of the palace removed.
The cardinals only elected the new Pope – Gregory X – after two years, nine months and two days, when the “blockade” was removed and the palace restored. Some years later, the seclusion process was regulated through the promulgation of the Ubi periculum constitution during the Second Council of Lyon in 1274 and the conclave was established: cardinal electors had to be locked in seclusion , in the place where the former pope had died, after a maximum mourning period of ten days.
The cardinals were supposed to mix during the scrutiny process and their food rationed progressively (they were fed normally for three days, then got one meal a day for five days and finally fasted on bread and water).
Contact with the outside world was limited, no cash movements could be made, cardinals had no access to money and could make no acquisitions.
These rules were soon scrapped as they were deemed too strict.
They were only re-introduced at the end of the 13th century.