Originally Posted by diotavelli
The Byzantine Empire did not have "many reigning Empresses" at all. They had four reigning empresses out of 90-odd monarchs in over a millenium.
Of the four, the first Theodora was a regent for two years and did not reign in her own right. Irene was deposed after a reign of just five years. Zoe had to marry twice and adopt a son in order to maintain her presence on the throne; in the end, she was deposed too, as far as I remember. Her sister, Theodora, ruled on her own but only for a year.
I don't think the Byzantines can be counted as exceptions to this rule any more than the English (Matilda), the Spanish (Isabella) or anyone else. Ruling queens in medieval times were few and far between and there were numerous reasons for this. They might make the game a bit more interesting but they wouldn't make it much more accurate.
As for fighting in battle, check out Sichelgaita, the wife of Roger de Guiscard (Norman ruler of Apulia). On one occasion (battle of Dyrrachium?) she fought in full armour and rallied the Norman army when Roger and his famous son, Bohemond, were unable to.
She may not be able to rule a faction but I wouldn't mind having her heading up a stack of Norman Knights.....