L. Rosengart, 21, Avenue des Cheamps-Elysées Paris
also 14 Rue du Ranelagh, Paris.
From 1922 to 1924* Lucien Rosengart produced powered bicycles named Le Moteurcycle which were also sold using the name Moteurcycle L. Rosengart These were powered by 98cc Train engines, and at least one model used a 206cc engine.
The company at one stage had some 4500 employees and produced 30 vehicles per day.
Rosengart obtained his driving licence in 1900 at the age of 19, and established a business making nuts and bolts in 1903. By 1909 he had sixty workers and was supplying both the bicycle and burgeoning automobile industies. A new factory was established in Saint Marné three years later and the product range included electrics, supplying the likes of Delage.
When the Great War broke out, he was 33 years old, rich, and well-known by senior members of the military, obtaining contracts which required a new factory in 1915 of some 10,000 square metres - roughly the size of a football stadium - and the following year another factory three times that size was constructed.
Come the Armistice, André Citroën expanded considerably before getting into financial strife. Rosengart offered support, they formed a partnership, and the famous French company survived. They amicably parted ways in 1922, but the following year Peugeot struck hardship and unto the breach stepped Rosengart, once more. For these and other acts he was awarded the Légion d'honneur in 1925, and thus the story continued for some decades with all manner of business adventures.
Possibly apocryphal, he once joked "I cannot ride in a French car which does not somewhere bear my name".
This great man died in Nice in 1976.
Sources: wikipedia.nl, contemporary advertising, rosengart-museum.de, club-l-rosengart-france.com
*Notes: Sources vary quite widely on production dates for the motorcycles.