The Sydow family or simply von Sydow is the name of two noble families. One, belonging to an ancient nobility, originated in Brandenburg was part of the German nobility. The other, more recent one, also of German descent, hailing from Stettin, later moved to Sweden and became part of the Swedish nobility. According to an oral tradition, the Swedish family is related to the noble German family von Sydow, known since the 13th century. However, there is no written evidence for this. Notable members from the German family. Hans Joachim Friedrich von Sydow (1762–1823), Prussian general.
https://en.wikipedia.org/wiki/Von_Sydow