What it says on the tin. Have a Habsburg as monarch of the *US, with a POD no earlier than 1773.
There's an extra Habsburg heir to Charles V, who gets the Netherlands. The Netherlands Habsburgs become Protestant.
As OTL:
- England colonizes North America
- The Stuarts inherit both British crowns
- Marriage of a Stuart heiress into the Dutch Habsburgs
- The ECW
- The extinction or removal of the Stuarts
Then
- Succession to the British crowns of a Habsburg prince of the Netherlands
Hey presto, a Habsburg is King over America.
Oh. Post
1773.
Well, one could have the Revolution crisis somehow resolved without American independence. (George III goes mad earlier?) America eventually becomes a Dominion, with a King or Queen.
But how to get a Habsburg into the mix? The Habsburgs are Catholic, and no Catholic can get to the British crown. If a Hapsburg scion converted to Protestant... Then some male of that line marries a British royal daughter, and when the Hanover line goes extinct, their son inherits. But I can't imagine any scenario for such a conversion. Also, I assume that a scion of the House of Habsburg-Lorraine is sufficient, as the male line of Habsburg went extinct before 1773. All subsequent "Habsburgs" are descendants of Maria Theresa and her husband Francis of Lorraine.
Well, let's go around Robin Hood's barn. Some Habsburg scion is adopted as King of Greece. He converts to Greek Orthodox. Four generations later, a younger son of this house marries a British royal princess - the youngest of three siblings, converting to Protestant. A brother succeeds but his only child dies childless. An older princess has one child who dies childless. The crown passes to the son of the third princess.
Fleshing this out:
George III goes hopelessly mad in 1773. The resulting political crisis leads to the regency of... no paternal uncles of George III, so his next eldest living brother, William Henry, Duke of Gloucester. (Whose extremely injudicious marriage has just been revealed, but who else is there?) I can't find out much about him. Assume he opposes coercion. At the very least there will be a political shakeup delaying action for a few months. I really don't know this period very well, so I can't really invent a path to compromise.
Assume one is found, and the Revolution is headed off with the creation of the Kingdom of America, with a Parliament meeting in New York.
1782 - Leopold, second son of Maria Theresa, has a sixth son *Johann.
1809 - Archduke Johann marries *Jeanne de Beauharnais, youngest stepdaughter of Napoleon. (Note: OTL, Johann married a postmaster's daughter.)
1815 - Johann and Jeanne have a third son, *Alexander.
1831 - *Alexander von Habsburg is chosen as King of Greece.
1841 - *Alexander marries *Sophie von Saxe-Alfeld, sister of *Queen Charlotte of Great Britain (wife of *King Albert I)
1845 - *Crown Prince Alexander of Greece born
1847 - *William, Prince of Wales born
1869 - *Crown Prince Alexander marries *Princess Dagmar of Sweden
1879 - *Prince William marries *Princess Ingrid of Sweden (niece of Dagmar)
1888 - *Prince George of Greece born (4th son of Alexander and Dagmar)
1881 - *Alexander II succeeds to the Greek throne
1884 - *Princess Anne of Britain born
1887 - *Prince Edward of Britain born
1894 - *Princess Alice of Britain born
1895 - *William V succeeds to the British throne
1907 - *Princess Anne marries *Lord Frederick Cavendish (3rd son of Duke of Devonshire)
1910 - *Martin Cavendish born
1913 - *Prince Edward of Wales marries Lady Margaret Gordon (daughter of the Marquess of Huntley)
1915 - *Frederick Cavendish KIA (his widow never remarries)
1916 - *Prince Charles of Britain born to Edward and Margaret
1918 - *Princess Margaret injured in a motor accident; left infertile.
1922 - *Princess Allce marries *Prince George; they are maternal cousins once removed, and paternal 2nd cousins once removed
1925 - *Prince Alexander Habsburg born
1938 - *Edward VII succeeds to the British throne
1941 - *Charles, Prince of Wales, dies of cancer (aged 25); *Princess Alice becomes heir presumptive, with *Prince Martin as her heir apparent
1942 - *Prince Martin marries hastily, to *Lady Emily Bentinck; the marriage is a failure and produces no children
1951 - *Princess Anne dies (aged 67); *Prince Martin is now heir presumptive to King Edward; *Prince Alexander is heir presumptive to *Martin
1962 - *Martin I succeeds to the British throne; *Prince Alexander is heir presumptive to *King Martin, who is childless after 20 years of marriage to *Queen Emily
1973 - *Alexander I of Habsburg succeeds to the British throne. He is also King of the Dominions of America, Australia, and South Africa.
Exactly 200 years after the PoD.