9 March 1831
The elite French Foreign Legion was founded by King Louis-Philippe as a military unit to support the conquest of Algeria, which the French had invaded the previous year. It absorbed many refugees who crowded into France as well as unemployed soldiers, such as members of the Swiss regiments who had served the unpopular Bourbon regime. The unit tended to be badly motivated - as their reasons for joining were desperation and self preservation rather than patriotism. To forge the force into an effective military unit, the Legion quickly developed an incredibly austere code of discipline, far exceeding that of other contemporary units, including those of the regular French army. The legion's international character and the tradition of not revealing enlistees' backgrounds have helped to surround the Foreign Legion with an aura of mystery and romance. It was normally stationed in Algeria until 1962, when its headquarters were transferred to southern France, near Marseilles. The army's regiments were scattered throughout the world and fought in the First and Second World Wars, as well as in the Crimean War, the Franco-Austrian War and in Mexico.
References

Wallis, F. (2000). Nuusdagboek: feite en fratse oor 1000 jaar, Kaapstad: Human & Rousseau.| Britannica French Foreign Legion [online] Available at: www.britannica.com [Accessed on 4 March 2013]