Joe Rosenberg, for 99% Invisible:

Aristophanes’ system became the basis for Western punctuation. A partial thought — followed by the shortest pause — was called a comma. A fuller thought was called a kolon. And a complete thought — followed by the longest pause — was called a periodos. These rhetorical units eventually lent their names to the comma, colon and period we know today.

More punctuation followed. Medieval scribes gave us the earliest forms of the exclamation mark. And in the 8th century, Alcuin of York, an English scholar in the court of Charlemagne, quietly introduced a symbol that would evolve into the modern question mark. Ever since, we’ve ended our sentences with one of these three ancient marks, called end marks.

There have, however, been attempts to expand this typographical toolkit, and include other end marks. One such example has made it into dictionaries: the interrobang (‽).

I love these types of stories.