Traitorfish
The Tighnahulish Kid
I'd say that it's also because pre-modern dictators are often not percieved as "dictators", just as King or Emperors or whatever, who can be expected to go violently stomping around. It's only if the dictators actions are exceptional for our civilised, "modern" era that they are properly recognised.Well, we often don't know as much about the earlier dictators, and in general they weren't able to be as great a tyrant as the modern ones due to less technology.
Correct me if I'm wrong, but it often seems that the only well-known, pre-modern dictators who are usually recognised as such are Oliver Cromwell and Napoleon Bonepart, while even the absolute monarchs who pre-dated them are just seen as "kings". They may be seen as "tyrants", but that always seems to refer to their methods rather than their position.