What is the scope of this subforum?
Short version: Beginning of time through 450 AD.
Everything in Europe (and the immediate area) prior to the battle of Chalons -- i.e., the defeat of Attila the Hun -- in 453 AD. Everything after that is medieval. I admit that the year is somewhat random, but it's also close to the sacking of Rome by Alaric in 410 AD. I see Chalons as a watershed battle, since Rome was unable to win alone and had to bring in Visigothic help.
This year is frequently seen as the beginning of the "Early Middle Ages" (formerly called the "Dark Ages"), reinforcing this cut-off date.