Something that came up over on G+ – in the course of discussing how many pre-spaceflight eldrae are still around (answer: lots, even if you discount the deep-submergence infomorphs and Transcendent afterlife, and even if some of them spent a while as frozen heads) – which I repeat here for general edification:
Namely, the oldest eldrae currently extant would be Esitaria Cyprium-ith-Avalae Linlethar was born in -284, which makes them 7,406 at the time of the Core War. (Imperial years – call it 7,322 T-years, once you correct for different orbital parameters.)
For scaling purposes, that’s like having someone born, let’s see, post-Alexander and pre-Rome. Or, since they never had a set of Dark Ages there, approximately 1,000 years before the fully-functional steam engine.
(Non-exo) archaeology and history are a very different disciplines, at least until you get well into the pre-Imperial period.