BATTALION, a unit of military organization consisting of four or more companies of infantry. The term is used in nearly every army, and is derived through Fr. from It. battaglione, Med. Lat. battalia (see Battle). "Battalion" in the 16th and 17th centuries implied a unit of infantry forming part of the line of battle, but at first meant an unusually large battalia or a single large body of men formed of several battalias. In the British regular service the infantry battalion is commanded by a lieut.-colonel, who is assisted by an adjutant, and consists at war strength of about 1000 bayonets in eight companies. Engineers, train, certain kinds of artillery, and more rarely cavalry are also organized in battalions in some countries.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)