The Rau von Holzhausen are a noble family whose seat was located in Hesse, Germany.
[1][2] The head of the house of Rau was styled the "Freiherr [Baron] Rau von und zu Holzhausen," although they held several other titles, including an order from the Kaiser that their title, since it was ancient, was to be styled a level higher, thus giving it the title Graf (Count) Rau von Holzhausen.
[3] The family was connected to upper nobility and royalty through a variety of marriages and alliances, most notably through the mother of Queen Victoria of the United Kingdom.
They first received recognition by the Frankish ruler Charlemagne, and were granted a coat of arms.
This honor was in respect of the unwillingness to surrender of a member of the family (since being considered the first lord) during the Frankish ruler's wars eastward through what is now Germany, notably against the Saxons.