"The Köhl family originates from the principality of Jülich, from where they were expelled because of there religion. Arnold de Rogister was bailiff of the princely court of Jülich at Malmedy and married to Gertraud van Külchen.
Their sons Julius and Johannes left their homeland; the elder son settled in Chur, where he became a citizen in 1564; the younger one, Johannes, is said to have settled in Bergün.
The two brothers, in order to avoid possible persecution, took the name of their mother Külchen."
Hercules Sprecher von Berneg
1847, Sammlung Rätischer Geschlechter