While we're looking at the first Magna Carta (written in 1215), that was really only version 1.0.

There are many similarities, and some glaring differences, in the later editions. For example: it turns out that King John wasn't the only monarch to be a bit offended by that whole "twenty-five angry barons get to pillage the king's house" clause.

After 1225 they stopped rewriting the thing and it hasn't changed since, but they keep releasing it. In fact, it's one of the oldest bestsellers around.