Yes, Seborga was a joke! Tavo, however, has some claim. There is even a portrait of the Tavo royal family in Buck Palace reportedly! According to the font of all knowledge (...) "In the 19th and 20th centuries, Tavolara was ruled by the Bertoleoni family as the Kingdom of Tavolara, one of the smallest kingdoms on the planet. It is now simply part of Italy, although it was never formally annexed. In 1836, King Charles Albert of Sardinia visited the island and acknowledged Giuseppe Bertoleoni as an independent sovereign monarch. When he died in the 1840s, his eldest son became King Paolo I. After Italian unification, King Paolo actively sought recognition from Italy. During his reign, in 1868 the Italian government began operating a lighthouse on the northeast end of the island. Tavolara's sovereignty was reconfirmed in 1903, when Victor Emmanuel III of Italy signed a treaty of friendship with the nation. Tavolara, the royal graveAfter Paolo's death in 1886, he was succeeded by his son, Carlo I. In 1900, Queen Victoria sent the Royal Photographer to Tavolara in order to make an official portrait of the Tavolara Royal Family, and include it in her collection of royal portraits. Carlo was succeeded upon his death in 1928 by his son King Paolo II. Paolo went abroad, however, and left Carlo's sister Mariangela as regent in his absence. Queen Mariangela died in 1934, leaving the kingdom to Italy. Her nephew Paolo II still claimed the kingdom, however, and ruled it until his death in 1962. That year marked the installation of the NATO station and the effective end of Tavolaran sovereignty."
So, in the spirit of light-heartdness, any Tavolaran composers?!
More seriously, though, a perfectionist tackling this question would look at a map of Europe from our chosen period (which seems to be the Romantic era?) and see scores of German principalities, Italian kingdoms and republics, etc....and realise he would have his work cut out!!