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Why did Pope Gregory X establish strict rules for papal elections in 1274?

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Cardinals of the Catholic Church, dressed in red, sit at long tables in the Sistine Chapel during the 2005 papal election conclave, surrounded by ornate frescoed walls. — papal conclave Cardinals assembled inside the Sistine Chapel of the Vatican Palace for a conclave to elect a new pope; Vatican City, 2005.

Pope Gregory X established strict rules for papal elections in 1274 primarily to prevent the long, disruptive vacancies that had previously plagued the Roman Catholic Church.1

Following the death of Pope Clement IV in 1268, the cardinals failed to elect a successor for nearly three years. This vacancy was only resolved after local authorities in Viterbo took drastic measures, locking the electors in the episcopal palace, removing the roof to expose them to the elements, and restricting their diet to bread and water until they finally selected Gregory X as a compromise candidate.21

To ensure such delays would not recur, Gregory X issued the constitution Ubi periculum ("Where Danger Lies") at the Second Council of Lyon in 1274. This decree officially regulated the papal conclave—a term derived from the Latin cum clave ("with a key")—by mandating the strict seclusion of cardinals to expedite the election process.1324