Yet other absolutist royal families, notably the Habsburgs, would survive until the wreck of old Europe in 1918.

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Through clever intermarriage and conquest, the Habsburgs ruled as far afield as modern day Ukraine, Montenegro, Spain and the Netherlands.

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It was named after Archduke Joseph August of Austria, a prince of the Hungarian line of the Habsburgs, who reportedly deposited it in a bank vault in 1933.

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When the Catholic Habsburgs defeated the Protestant Palatine Elector Frederick V in 1620, they reduced Heidelberg Castle to ruins and carried off the contents of the library as spoils of war - by this time totalling over 3, 500 manuscripts and 13, 000 printed works - to the Vatican Library in Rome where they remain to this day.

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