But in 1415, mass media happened not on a TV but at, well, Mass. "This is the big thing about the Middle Ages," George Ferzoco, a medievalist at the University of Bristol, told me. "We tend to think that they had no such thing as a mass medium. The fact is they did. And that mass medium was the sermon, because everyone would regularly be at one. Priests would not only talk about what people should doing in order to lead a good life, but in some cases, they really did serve as kinds of newspapers. They would announce what was happening, the major news that came in from abroad."

Historian Donald Prudlo echoed that framework: mendicant friars -- preachers who brought the gospel to the people by foot, opting out of monastery life -- "were sort of the mass media of the age. If you take the Internet and Twitter and television and radio, they were it. These were the men who traveled all around Europe. And in addition to their preaching, which sometimes lasted several hours, they would intersperse their religious material with news of the Holy Land, news of England, news of the Spanish succession."

The clergy were, in a sense, the 15th-century's TV screens, the displays that conveyed the news. But just as information does not begin in your TV set, 15th-century friars and preachers got their news from somewhere -- and that somewhere, in the case of the 1415 resignation, was Constance, the town in what is now southern Germany where the council had convened to negotiate who would lead the church. Of course, those at Constance were the first to know any news. "Probably about 900 of the greatest minds of Christianity are there, and the city would be packed with I don't know how many times that number feeding them and housing them and clothing them. So that is to say that there is also a huge rumor mill around," Catholic historian Christopher Bellitto told me.

"Paddypower.com is just the latest version of people wondering what is going on and who is going to be the next pope," he added.

"These were major, major events," said Ferzoco. "Almost every principality and republic in Europe had representatives there; bishops were there with their retinues." And, he added, "On top of that you've got a lot of people hired for the occasion. They would have shipped in scribes from all over the place, so that they could make copies of all the documents."

"Imagine," he continued, "what it's like to have a major international meeting lasting a few years, and you've got to discuss written texts. Well you've got to have an army of people writing this stuff out, nonstop, day and night. So all of these people together would have been potential news sources. They would have sent news back to their home cities, or indeed to people who they deem are important or interested."

From Constance, news traveled outward through a network of messengers on horseback. Couriers "would take documents out of Constance, go to a town 20 or 30 miles down the road, transfer things there to a fresh person and a fresh person and so on," said Ferzoco. Medievalists I spoke with estimated that this sort of "Pony Express" system could have conveyed the news of Gregory XII's resignation to major European cities such as Paris in something like a week. (One said "within a week or so"; the other put it at "at least a week.")