I love the fact that the people would actually lock the cardinals into a building and not let them out until a pope was elected. And if needed, put them into a building with no roof to help speed the process up a tad!
There were only two incidents of actual conclave, iirc--though the name has stuck. The people of Rome, upset about the cardinals' enjoying their stay a bit to much to bother with the business at hand, locked them in the building with the leaky roof with (con) a key (clave), where they were forced to subsist on water, wine, and bread until they delivered a pope.
I want to say the 1100's, but I'm fuzzy on that. I also want to say that there was a similar event a couple of hundred years later.
Anyway, it certainly leads to daydreams about the five Great Patriarchs: "You may come out when you figure out how to concelebrate . . ."
hawk