The Vickers-Berthier (often called simply VB) is a British light machine gun based on the design of French General Andre Berthier (the author of Berthier Rifles). It appeared in 1909, later was tested by US Army and formally adopted in 1917 but never produced. In 1925 Vickers-Armstrong Ltd purchased the rights for the machine gun. Mk.1 appeared in 1928, and Mk.2 in 1928, and Mk.3 in 1931. While Vickers-Berthier was tested by British army, it lost to Bren, but it was Indian Army that adopted Mk.3. The machine gun was produced both in UK and in India, by Ishapore Rifle factory. VB was also purchased in small numbers by Latvia and Bolivia. Vickers K machine gun is a development of VB.