I recall reading something aeons ago to the effect that the subtractive notation was not common when the numbering system was first invented, but was added (ha)

I recall reading something aeons ago to the effect that the subtractive notation was not common when the numbering system was first invented, but was added (ha) much later. I've had a quick search for something definitive now, but no joy, so the story may be apocryphal. In any case, if true it would change the record for 'longest (roman numeral) date so far' to 1999 I think (MDCCCCLXXXXVIIII) We still see subtractive notation eschewed in various places, most notably roman numerals on clocks, though that may be more for aesthetic balance, as the 4 opposes the 8. In almost* every variant you have to write 8 as "VIII", and because IV doesn't balance so well, you usually see IIII on clocks. * There are cases where irregular subtractive forms are in use - so 8 could be written as IIX.