LEGION, in early Rome, the levy of citizens marching out en masse to war (Lat. legio), like the citizen-army of any other primitive state. As Rome came to need more than one army at once and warfare grew more complex, legio came to denote a unit of 4,000-6,000 heavy infantry (including, however, at first some light infantry and at various times a handful of cavalry) who were by political status Roman citizens and were distinct from the "allies," auxilia, and other troops of the second class. The legion aries were regarded as the best and most characteristic Roman sol diers, the most trustworthy and truly Roman; they enjoyed better pay and conditions of service than the "auxiliaries." In A.D. (death of Augustus) there were 25 such legions; later the number was slightly increased; finally about A.D. 290 Diocletian reduced the size and greatly increased the number of the legions. Through out, the' dominant features of the legions were heavy infantry and Roman citizenship. They lost their importance when the Barbarian invasions altered the character of ancient warfare and made cavalry a more important arm than infantry, in the late 3rd and 4th centuries A.D. (see further ROMAN ARMY). In the middle ages the word "legion" seems not to have been used as a technical term. In modern times it has been employed for organizations of an unusual or exceptional character, such as a corps of foreign volunteers or mercenaries. Perhaps the earliest example of this was the Provincial Legions formed in France by Francis I. (see INFANTRY). Napoleon, in accordance with this precedent, em ployed the word to designate the second-line formations which he maintained in France and which supplied the Grande Armee with drafts. The term "foreign legion" is often used for irregular
volunteer corps of foreign sympathizers raised by states at war, often by smaller states fighting for independence. Unlike most foreign legions the "British Legion" which, raised in Great Britain and commanded by Sir de Lacy Evans (q.v.),, fought in the Carlist wars, was a regularly enlisted and paid force. The term "Foreign Legion" is colloquially but incorrectly applied to-day to the Regi ments strangers in the French service, which are composed of adventurous spirits of all nationalities and have been employed in many arduous colonial campaigns.
The most famous of the corps that have borne the name of legion in modern times was the King's German Legion (see Beamish's history of the corps). The electorate of Hanover being in 1803 threatened by Napoleon, and no effective resistance being considered possible, the British government wished to take the greater part of the Hanoverian army into its service. But the acceptance by the Hanoverian government of this offer was de layed until too late, and it was only after the French had entered the country and the army as a unit had been disbanded that the formation of the "King's German Regiment," as it was at first called, was begun in England. This enlisted not only ex-Han overian soldiers, but other Germans as well. In January 1805 it had become a corps of all arms with the title of King's German Legion. It served in many of the campaigns of the Napoleonic wars but its title to fame is its part in the Peninsular War, in which it was an acknowledged corps d'elite.