If Duke Albrecht had succeeded as king, how would the present head of the house be styled? We know that the head of the royal house of Wittelsbach is styled as the DUKE of Bavaria, despite the fact that his grandfather did manage to succeed to the throne -- Ludwig III, the last king.

This title, of course, should not be confused with Duke IN Bavaria: that branch of the house became extinct in the male line back in the 1970's. If I understand correctly, those Wittelsbachs were originally styled as Ducal Serene Highness -- until elevated to Royal Highness in 1845. And like the junior members of the Württembergs, they did have succession rights to the throne. That was why the future Empress Elisabeth of Austria was made to renounce her rights to the Bavarian throne.

To be sure, the present head of the house (Franz) is unmarried, while his only brother (Max) is the father of five daughters but no son. He was adopted as Duke in Bavaria by his maternal great-uncle; but facts are facts: that branch of the Wittelsbachs (succession to which is in the male line) is officially extinct.

By contrast, the royal branch is still very much alive and kicking, as the male line descent of King Ludwig I does not appear to be anywhere near on the verge of extinction. Like I said, I see some poetic justice in the fact that the title Prince(ss) with the qualification of Royal Highness is unlimited in Bavaria -- since the dynastic descent of King Maximilian II quickly became extinct. Basically, the cousins could be thought of as having the children the "mad" kings (Ludwig II and Otto) could/would not have.