October 31 is Halloween to some. This year, it’ll also be the 507th anniversary of the day Martin Luther nailed his Ninety-five Theses to the door of All Saints’ Church in Wittenberg, Germany. That’s as good a day as any to celebrate the beginning of Protestantism, though it took another dozen years or so to formally organize the new denomination.
It was not the first major split in church history, nor was it the last, but Catholics and Protestants have been sparring about it verbally (and sometimes physically) ever since.