There are two places in Germany called "Achenbach": Near Siegen (today a part of the town Siegen) exist a little valley, the rivulet in this dale is called "Achenbach", and the farm nearby also "Achenbach". The owner of this farm in the Middle Ages, german nobles,were called "von Achenbach". (see: Kurt Schutte: "von Achenbach". In: Familienzeitung des Geschlechts Achenbach, Band 1, Heft 2, Celle, Dez. 1970) But also the inhabitants of this farm, the landholders and farmers, were called "Achenbach". One of these families went to the town Siegen. Their genealogy is called "Achenbach 1" (see: Deutsches Geschlechterbuch, Bd. 163, [3. Siegerländer Band), Limburg/Lahn (C. A. Starke) 1973, p. 1-224).
Also the second family has its origin in the farm Achenbach. The family is called "Achenbach 2" (see: the same book, p. 225-250) The third family of Siegen and Ferndorf near Siegen seems to come also from this farm, the members were often teacher and pastors, famous members are the artists Andreas and Oswald Achenbach (p. 251-268).
Perhaps also the family "Achenbach 5" of Anstoss may have also its origin in the farm Achenbach near Siegen. It is described on p. 269-300.
Not so far away from Siegen exist near Laasphe a village, called "Achenbach". When in the Middle Ages someone of this hamlet went into an another village in the neighbourhood he was called with his birthplace: "Achenbach-Johann", "Achenbach-Henry". Therefor exist a lot of families called "Achenbach", which are not related. They livedin the county Wittgenstein an Hessen.
To theses families belong the Achenbachs from Niederhörlen (later Münchhausen and Freudenberg) called "Achenbach 6" (p. 303-312)and the Achenbachs of Arfeld (Achenbach 7) near Berleburg (later Weidenau)(p. 313-323).
The word Achenbach is a composit of two words "Ache" and "Bach". "Bach" means a little rivulet. "Ache" is an old german word and means "water", the same origin as in latin "acqua", in French"Aix". Thank you and excuse please my English. Rotger