Rome: Rise and Fall of an Empire is a 13-episode documentary series that starts at the very end of the Roman Republic, and then follows the ups and downs of the empire through the 5th century and the overthrow of the boy emperor Romulus Augustulus in 476 AD.
This is an extremely well-done series that originally aired on the History Channel (remember when it was about more than nonsensical ancient aliens shows?). The series is heavy on re-enactments interrspered with commentary from academic experts who do an excellent job of describing and contextualizing the events of the ancient Rome.
Someone has posted the entire series to YouTube:
Episode 1 – The Rise and Fall of an Empire
Episode 2 – Spartacus
Episode 3 – Julius Caesar
Episode 4 – The Forest of Death
Episode 5 – The Invasion of Britain
Episode 6 – Dacian Wars
Episode 7 – Rebellion and Betrayal
Episode 8 – Wrath of the Gods
Episode 9: The Soldier’s Emperor
Episode 10: Constantine the Great
Episode 11: The Barbarian General
Episode 12: The Puppet Master
Episode 13: The Last Emperor