Originally Posted by
Creepcruncher
IMO, William's army would win.
Roman legionaries didn't have much arm/leg armour, or face protection, so William's sergeants and footmen were better armoured.
William's cavalry would also have been more heavily armoured.
Get a picture of a roman legionary, then an 11th century knight. Note the difference.
Going purely off equipment, I'd say William. William was also a great general, meanwhile Roman generals could either be fantastic or awful, so again, I'd put my money on William.
Now, according to Wikipedia, William's army at Hastings was 7,000-12,000 men strong. A Roman legion was around 5,200 men and 120 auxiliaries in the Imperial period. William could have easily had twice as many men as a legion. So, numbers wise, again I'd bet on William.
The Romans had great tactics etc, but they wouldn't have been well equipped enough, or used to Medieval warfare. The Byzantines stopped using legionaries and comitatenses well before Hastings, so the Romans would have been pretty obsolete by then.
So, yes, William would have won.