I'd have to go along with Spartans resembling Mandalorians the closest also, IMHO. Whilst martial prowess and personal honour were important in all of the ancient Greek city states, these things are what Sparta was all about, like the Mandalorians. Also Sparta used an underclass of levy soldiers (helots) from a conquered neighbour alongside their own troops, as did the Mando's, at least according to dialogue with Mira. Although the Spartans didn't raze any cities to provoke their enemies into war, personally I don't think that they would have had too much of a problem doing so... its just they didn't have to, they had plenty of enemies to fight throughout their history, and didn't need to resort to such extreme provocation to get into a rumble. The main reason I think they are so alike is that they were both doublehard!