Here’s another potential post-World War I Eastern European monarchy snuffed out in the cradle. If such a thing is imaginable, it was even less existent than the Finnish and Lithuanian kingdoms.
The situation began with the signing of the Treaty of Brest-Litovsk on March 3rd, 1918. Under this treaty, the new Bolshevik government in Russia essentially cut their losses on the war and ceded territory conquered by the Central Powers (Germany, Austria and the Ottoman Empire) to end the war on the Eastern Front. The German-controlled territory, stretching from the Baltic to the Black Sea, was known as the Ober Ost, and included at its north end three governates of the Russian Empire: Courland (modern southern and western Latvia), Livonia (northeastern Latvia and southern Estonia) and Estonia (northern Estonia).
The local authorities moved quickly to establish government. Courland declared itself the Duchy of Courland and Semigallia on March 8th, and Livonia and Estonia formed the Duchy of the Baltic State on April 12th. Both declared personal union with the Kaiser, i.e. Wilhelm II was the Duke of the two new duchies. Germany recognized the two as one United Baltic Duchy On September 22nd, which would thereafter be a constituent state of the German Empire, like Prussia or Bavaria. On November 5th a Regency Council was formed, which met at Riga and elected Duke Adolph Frederick of Mecklenburg-Schwerin as the new Duke.
Adolph Frederick led a pretty remarkable life. The son of the Grand Duke of Mecklenburg-Schwerin by his third wife, Adolph Frederick traveled to Africa and led several expeditions to explore Lake Chad and the Congo river basin. He was governor of the German Togoland colony from 1912 to 1914, and did well enough to be invited to come back and visit when Togo declared independence in 1960. He was a member of the International Olympic Committee for 30 years and chaired the West German Olympic Committee. He died in 1969, aged 96.
Adolph Frederick was a direct descendant of George I of Great Britain:
George I > Princess Sophia Dorothea of Hanover> Princess Sophia Dorothea of Prussia > Margravine Friedrike Dorothea of Brandenburg-Schwedt> Duchess Sophia Dorothea of Württemburg > Grand Duchess Elena Pavlovna of Russia > Paul Frederick, Grand Duke of Mecklenburg-Schwerin> Francis Frederick II, Grand Duke of Mecklenburg-Schwerin > Duke Adolph Frederick of Mecklenburg-Schwerin.
At any rate, it didn’t last. One of the first effects of Germany’s defeat on November 11th was the cancellation of the Treaty of Brest-Litovsk, and modern Latvia declared itself independent on November 18th. The Regency Council lasted until November 28th, when it quietly dissolved and Adolph Frederick withdrew his candidacy to pursue his African business interests. The German occupation handed over power in Estonia to a provisional government, which then had to contend with an invasion from the Soviets, who were hoping for an easy conquest. The Estonians fought back, however, and expelled all Soviet troops by February 24th, 1919.
Under most Germanic succession, inheritance would be limited to males in Adolph Frederick’s family. However, not only did he have no sons, the last male member of the House of Mecklenburg-Schwerin died on July 31st, 2001, aged 91. However, Adolph Frederick did have one daughter, Duchess Woizlawa Feodora of Mecklenburg-Schwerin, who is (as of September 2012) still alive and 94 years old. If we were to assume some modernization along the lines of the laws of succession to the British throne, she would be the current pretender, and her heir would be her eldest son, Prince Heinrich VIII Reuss of Köstritz, followed by Heinrich VIII’s son Heinrich XX. (The Reuss family name every male child “Heinrich”,
starting over around the start of each century. The highest-ever was Heinrich LXXII [1797-1853], or, in English, “Henry the Seventy-Second”. ) If we went so far as to employ a Swedish-style succession of gender equality, the heir to the current pretender would be the Duchess’s daughter Princess Feodora Reuss of Köstritz, and Feodora’s heir would be her son Count Constantin of Stolberg-Wernigerode.