For some reason this made me think of Megalomania on the Amiga.... loved that game !
Can't think of anything recent that fits your criteria though.
The Civilzation games were like that... Lost many a month playing civ2 back in '98...
Aye exactly my thoughts to, although civ isn't an rts
Could also be the original Age of Empires, you start off with Stone Age and advance up to Roman or Egyptian.
What we need is a new rts which has the huge research scale of Civ IV and timeline, but with the twist of real-time events such as plagues, volcanoes, wooly mammoth extinction, wars, etc and the grand battle epics with huge number of units like Rise Of Nations or Age of Empires II. Or Age of Empires I, II & II all in one big game!