Noel you do know that Henry IV was not the senior line taking the throne and his reign nor that of his son Henry V were opposed by the senior genealogical line. Only during the reign of his grandson Henry VI did the Yorks really oppose and was the senior line restored during the reigns of Edward IV and Edward V assuming that Richard, duke of York was the real father of Edward IV otherwise we are opening up another line of potential heirs.
We also must assume that both Edward V and his brother Richard, duke of York were murdered even though the 100% proof of that was never given. Any legitimate line from either of them would precede the line of their sister Elizabeth of York.
There also is the issue of James VI and I being, like his mother and grandfather before him not a born Englishman. So technically another line of succession could have legally directed the throne to his first cousin Arbella Stuart. Their paternal grandmother was born on English soil the daughter of an English princess and a Scottish noble. Margaret's sons were born in England as was Arbella so not the senior line but the senior English line.
If you take in account Henry VIII's bill of succession the Stuarts should not have succeeded and as that was the bill that gave succession rights to the woman who left the throne to the Stuarts there is another difficulty.
Lastly was there not a marriage between an uncle and niece in the line of Franz? I believe such marriages were illegal in England, in that case would the offspring still be legitimate when it comes to English law?
Are you deliberately being disingenuous? I am aware and do not dispute that "is a FACT (not a claim) that Franz is the senior co-heir general of King Charles I of England, France, Scotland, and Ireland". As I wrote, notwithstanding this genealogical fact, the Duke males no claim on the THRONES that his Stuart ancestors once occupied, and nor have his ancestors for generations. Therefore you, and others of like mind, cannot be termed 'followers'.
I have not used the term "followers", nor has any other Jacobite in this forum. You have created a straw-man.
Franz makes no claim to be King of Bavaria. He knows that he is the great-grandson and male-line heir of King Ludwig III of Bavaria, and that he is the senior co-heir general of King Charles I of England, Scotland, France, and Ireland. His adherents (whether Bavarian, English, Scottish, or Irish) know likewise.
Moreover, since 1066 English constitutional history has repeatedly demonstrated that, unlike France, genealogical seniority does not automatically confer succession.
There were a number of times in English history before 1689 when a cadet prince took (usurped?) the throne. But every single time this was corrected in a subsequent generation.
It is only in 1689 and then in 1714, that the throne was taken by a junior line without ever being restored to the senior line (at least, thus far).
There is no point debating this much-mauled shibboleth except to point out that Common Law is trumped (an unfortunate choice of phrase) by Statute Law and that James II abandoned his thrones (quite literally) by flight, creating circumstances in which the Parliament asserted, yet again, its constitutional rights.
In 1648 Charles II left England in much the same way that his brother James II left England in 1688. In neither case, did the brother intend to "abandon his throne". In the case of James II, within three months he was in Ireland fighting for his Irish crown. But the hateful Williamites and their current-day defenders think of Ireland as some sort of sub-human nation, not worthy of defending. It is just ridiculous to state that James II "abandoned his thrones".
Finally, your references to Elizabeth Windsor are childish and unnecessarily demeaning (to you). Even with your world-view, would she not be styled 'Princess Elizabeth of Greece and Denmark'?
Presumably one is not allowed to use such terms as Henry Plantagenet, Henry Tudor, James Stuart, William of Orange, or George of Hanover. How ridiculous to make a fuss over the use of the term "Elizabeth Windsor".
The Williamites and Hanoverians - and their followers! - are religious bigots. For hundreds of years the kings of England and the kings of Scotland were Catholics.
Noel S. McFerran