A 'what if' that I've contemplated for a while, what if Maria Theresa von Habsburg had lost the War of the Austrian Succession?
What would the consequences have been?
For example, Maria Theresa secured the Hungarian throne independently of the Austrian inheritance, would the Franco-Prussian alliance against her allow her to keep it? Or would they try to push her off the Hungarian throne as well and risk a widening of the conflict into Eastern Europe and drawing in the Ottoman Empire?
Not to mention the uniting of Austria, Bohemia, and Bavaria in the person of Charles VII and the Wittlesbach dynasty would create a real threat to Prussia's desire for dominance in the HRE. If Charles's line dies out like it does in RL, would Maria Theresa have a chance at getting her Austrian inheritance back anyway? Or would it just detonate a much larger War of Bavarian Succession than the small war in RL?