Today is the Feast Day of the Lateran Basilica of St. John in Rome.
True enough, Protestants don't officially celebrate Catholic feast days. But that's no reason not to take advantage of them to explore some history, and the many-centuries history of the Lateran is fascinating. Probably all (if anything) that most of us know about it has to do with the Fourth Lateran Council in 1215, when the doctrine of transubstantian was affirmed. Here's some more.