Pope Alexander III in his constitution in 1179 gave the right of electing the Pope to the cardinals. It solved many problems but it was the cause of another problem: the time of the conclave became too long. The problem was even bigger because the number of the cardinals was limited. After Alexander III’s death the number of the members of the syndicate of the cardinals was between 10 and 20. During the 13th century their number was never more than 30. The period of the ”sede vacante” (the period when there is no pope) became longer and longer. Sometimes it was several years long. Even though the Christians personally could not take part in the election, they became deeply worried about the long conclaves, because they noticed it was bad for the Church. The cardinals had to be ‘locked up’ to finish the election as fast as possible four times in the history of the pope elections, for example in 1216 in Perugia, the Romans in 1241 closed them into Semptimus Severus’ palace which was on Palatinus Hill and it also happened in 1243 in Anagni.
The last and perhaps most famous „lock-up” was in Viterbo after Clement IV’s death in 1268 when the syndicate of the cardinals could not decide, even though the king himself also tried to press them, so the people decided to close them into the palace. Firstly, they bricked up all the doors. It was not enough. So they opened the roof and the cardinals got just water and bread to eat through the open roof. This conclave elected Gregory X and it lasted 2 years 9 months and 2 days long.