A Brief History of the Marque
1898-1905 Cudell & Co., engine and vehicle plants, Aachen
1906~1945 Cudell-Motoren GmbH - Reinickendorfer Strasse, Wedding, Berlin 
Max Cudell, one of the oldest vehicle manufacturers in Germany, built tricycles, quadricycles and motorcycles under licence from De Dion & Bouton from 1898 to 1905. Martin Stolle of BMW fame worked with Cudell from 1903. Wilhelm Wenske, later of Adler, Opel and Horch, also worked with Cudell, as did Karl Slevogt.
Their licence was for Germany, and when they began shipping vehicles to Britain the English firm, De Dion-Bouton, Ltd., took them to task and they lost their licence as a result; financial ruin followed and they entered bankruptcy in 1905.
Cudell recovered from the disaster (which would no doubt have been abetted by the financial slump), and in 1906 they produced a bicycle auxiliary engine. They then built what is believed to be the forerunner of the outboard motor, along with carburettors, stationary engines and more. They were still in business in 1945.
It appears that the firm also built Argus engines under licence.
Cudell engines were used by Christiansen of Denmark, Riley of Britain, Victoria of Nuremburg, Leutner (Leitner) of Riga (and later Ukraine), and Phoenix of Budapest.
Notes. 1. The company dates require revision. Names are those used in advertising of the period.