Enlighten me, Please!
Since the Reformation, when the keeping of records for normal folks started, German royals (i.e. members of immediate imperial families) have, with few exceptions, only married other German or foreign royals.
People are far more likely to be a descendant of Edward Longshanks than a Landgrave of Hesse. Not only because King Edward lived a few centuries earlier and thus has more descendants than most Hessian landgraves, but also because his children married into the nobility, his grandchildren into the gentry etc., while nearly all children and grandchildren of Landgraves of Hesse married other German royals. Even a daughter of a Landgrave marrying an untitled nobleman would be an exception. It was a very closed caste.
Yes, even the strict ebenbürtige Landgraves fathered bastards and morganauts, but they (at least the proven ones) are not as plentiful as people like to imagine and were usually integrated into the non-immediate nobility, which was almost as endogamic as the royals.
A phenomena like the Romanovs, i.e. somebody becoming monarch without their paternal ancestors having been princes since times immemorial, was simply not possible in Germany. Who and what were the ancestors of the Romanovs in the 15th, 14th and 13th century? We have no idea! But we know exactly who and what the Landgraves of Hesse were in those centuries and who they married. And that was not commoners!
