I’d like to do a longer post about the history of papal elections as I think their principles could be relevant to consider for the present or future, but I only have time to post this tonight.

For example, some questions come up about how Catholics would elect if the cardinals all died in a war for example or something; a little research indicates for example that cardinals were not always the exclusive electors of the pope, and that a “general imperfect council of bishops” might elect a pope if cardinals cannot, or a papal election might occur in some other way so long as it gains a kind of “universal acceptance by Catholics”.

The election of a pope exclusively by cardinals is only from 1059 onward I believe:

The selection of the pope, the bishop of Rome and supreme pontiff of the Roman Catholic Church, prior to the promulgation of In nomine Domini in 1059 varied throughout history.

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The absence of an institutionalized procedure of papal succession facilitated religious schism, and the Catholic Church currently regards several papal claimants before 1059 as antipopes.

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In 1059, Pope Nicholas II succeeded in limiting future papal electors to the cardinals in In nomine Domini, instituting standardized papal elections that eventually developed into the procedure of the papal conclave.