I believe a Roman soldier was expected to be able to do 20 Roman miles (just under 30km) in a 5 hour marching day. However I suspect that rate would be reduced for a long distance march like this and they would probably need to take say one day in ten (?) resting. So say 20km a day with a rest day every 10. That said the larger the army the less they will do each day. No mater how well organised the army is minor incidents in the middle of the column will tend to spread the column out and the front must slow down to prevent that happening (and the column becoming too vulnerable). The same is actually true of modern motorised army columns. The front vehicle will do a nice steady 40 mph say but the poor back vehicles will be doing 60mph one minute and 20mph the next. Excatly the same as what happens in a traffic jam and exactly the same thing happens with a large army on foot.
Just a thought - it might be worth messaging The Ace (in case he dosen't look in on this particular thread) as I believe he is in a Roman Reenactment society/club and can probably give you a much better answer!
Just a thought - it might be worth messaging The Ace (in case he dosen't look in on this particular thread) as I believe he is in a Roman Reenactment society/club and can probably give you a much better answer!