The surname in the Netherlands of Liomenman was changed from Lemon man to Citroen (lemon) when the family moved to France. Later a couple of dots appeared over the e. Andre Citroen was an engineering graduate and well known for popularising the double chevron gears he introduced. He was instrumental in the production of munitions during the first war, keeping 35,000 people busy at teh Renault works. In 1919 he went into the car making business and became hugely successful. After the depression Citroens designs radically changed when the ex Voisin engineer Andre Lefebvre joined Citroen (after a couple of years at Renault) to work on the monocoque independent suspension Traction Avant project. Working with designers at Citroen they created some of the most avant garde cars of the 20th century. The "11CV" Traction Avant continued in production, continually "improved" for decades, with 4 and 6 cylinder engines, mostly in France but with production also in Belgium and the UK (Slough). The British right hand drive cars were called the Light 15.
In 1954 Citroen innovated the hydro-pneumatic suspension on the cars, which was used the stunning successor which was the DS introduced in late 1955. A simplified version was the ID which was introduced in 1965. When Maserati was in difficulties Citroen purchased a majority shareholding and this cooperation led to the Citroen SM which was built in Modena until 1975.