Dux Bellorum will be published by Osprey Publishing later on this year. These are an update and reformat of the great Arthurian rules, "Glutter of Ravens" by Daniel Mersey.
Evidently, this is the first in a new series of 64 page wargaming books by Osprey Publishing. I hope that the series produces many similar titles. The second one (not sure of the date) will be "A World Aflame" which will cover conflicts from the interwar period (1919-1939). A special section in that one will cover "A Very British Civil War" which is of course the fictional account of a Civil War in Great Britain, in the 1930s. Loads of cool stuff.