I know that there have been numerous intermarriages among the descendants of Queen Victoria of Great Britain. Similarly, the intermarriages among the descendants of King Maximilian I of Bavaria are legion (consider his two marriages, which produced a total of 13 children, although they didn't all survive to adulthood. That being said, a number of his daughters made prestigious marriages into established royal dynasties).

But what if one were to restrict discussion to only the descendants of his eldest son and successor, King Ludwig I? How many intermarriages have there been among them? The reason for my asking is that he is the nearest common ancestor to all the Bavarian royals today, since he represents the only surviving dynastic line of his father, the founder of the royal branch of the house of Wittelsbach (I believe the male line of the ducal branch is on the verge of extinction).

Of course, I realize that the unions have not all involved agnates: the last time this happened was the first cousin marriage in 1950 of Prince Ludwig and Princess Irmengarde (both being grandchildren through sons of Ludwig III, the last king of Bavaria).

Aside from this example, there was the 1919 marriage of Prince Adalbert of Bavaria (a great-grandson, born in 1886) and Countess Auguste von Seefried auf Buttenheim (born in 1899, a great-great-granddaughter, who was also a great-granddaughter of Emperor Franz Joseph and Empress Elisabeth of Austria-Hungary);

The 1921 marriage of Prince Konrad (a great-grandson, born in 1883) and Princess Bona Margherita of Savoy-Genoa (a great-granddaughter, born in 1896;

The 1938 marriage of Prince Eugenio of Savoy, the 5th Duke of Genoa (a great-grandson, born in 1906) and Princess Lucia of Bourbon-Two Sicilies (a great-great-granddaughter, born in 1908);

The 1991 marriage of Duke Philipp of Württemberg (born in 1964, a great-great-great-great-grandson) and Princess Marie Caroline, Duchess in Bavaria (born in 1969, a great-great-great-great-granddaughter).

Can anyone name other examples? It's interesting to note that three unions have been intermarriages involving the descendants of Prince Luitpold (who eventually served as regent of the kingdom on behalf of his mentally incapacitated nephews, Kings Ludwig II and Otto) and Prince Adalbert (founder of the Spanish branch of the Wittelsbachs), the two younger sons of King Ludwig I.