Quote Originally Posted by diotavelli
Countries that observed the Salic Law did not have queens. Other countries, notably England, Scotland and the Eastern Roman (Byzantine) Empire, did have regnant queens - some of whom never married.

There is no reason why countries not historically observing the Salic Law couldn't be ruled by a queen in M2:TW, if no male heirs were available and the right mod was in place.

The interesting thing would be that, just as a princess can do the dirty on you in the current game and run off with an enemy general, so could your queen.

Imagine it: you've accumulated 44 provinces, you're just about to seal Scotland's position as the mightiest power in Europe and then your 74 year old Queen Agnes I gets her head turned by a dashing young Italian nobleman less than half her age and you lose the game........
It's a bit more complicated than that. Salic law was a fabrication of 14th-century French bureaucrats seeking to legitimise the royal claims of the Valois dynasty. In reality succession was determined by certain customs, some of which were theoretically set in stone, but all of which were occasionally ignored for convenience.

There is of course huge geographical diversity when it comes to the role of female members of royal families. Frontier societies tended to be more relaxed; thus, Queen Sibylle, daughter of Amalric, King of Jerusalem and brother of Baldwin IV, could become regent of the kingdom in the absence of a suitable male claimant (who soon arrived in the form of Guy de Lusginan).

Coding such a complex and varied system would of course be impractical and would probably skew the results (as has already been pointed out, female monarchs were ultimately few and far-between) and as such it is sadly for the best that CA chose the broadly historical model of an all-male dynasty - even if, as the OP pointed out, the death of all male pretenders should not really herald the end of the game if female family-members remain.