Louis Kahan was born in 1905 to a wealthy family of tailors in Vienna, Austria. Due to his family background from an early age Kahan received a great deal of training in art and design. In the 1920s-30s Kahan's reputation as an artist began to rise resulting in gaining apprenticeships and working with such famous artists as Matisse, Dufy and Vlaminck.

By the time war broke out in 1939, Kahan, who was Jewish, had already emigrated from his native Austria. He enlisted in the Foreign Legion towards the end of the year, and was sent to North Africa for training. Appreciative of his art background, Kahan received the nominal position of resident war artist for the Foreign Legion and French forces in North Africa. When the 13th DBLE was formed and sent to France for their brief winter training before being shipped to Norway, Kahan came along and was later transferred into the unit. However, when the 13th DBLE shipped out Kahan was given orders to return to North Africa, thus ending his first stint in the 13th. After France's capitulation, Kahan remained in North Africa as a civilian working as a free lance sketch artist. When Free French forces landed in North Africa Kahan again volunteered for service. He was once more given the assignment of war artist for the Free French forces, and served in the 13th DBLE. Yet, after a few months Kahan left the Free French Army and the Legion, instead volunteering for the Red Cross where he also served as an artist. At a time when the Red Cross was not allowed to take photos of POWs, the sketches of them by Kahan often was used as the only definitive proof that they were alive in captivity. He also ran a successful side business of making portraits of Allied Servicemen to send as souvenirs home.

After the war Kahan briefly lived in US before eventually journeying to Australia where his family had already emigrated to before the war. Throughout the rest of his life Kahan's artist career flourished with many of his works residing in museums around the World. He lived to old age of 97, dying in Melbourne, Australia, in 2002.