It is sad to have to say that throughout the long history of machine guns in the British service there has never been one of British design actually adopted.
The development of the Vickers MMG was a long, drawn-out process that started with the designs by Sir Hiram Maxim in the 19th Century and the Maxim Machine Gun.
The advent of the development of the Maxim gun and the formation of the Maxim Gun Company in 1884 with Albert Vickers as Chairman, introduced the first true machine gun to the British service.
The Maxim MG was first purchased in 1887 and one instructional gun was issued, per Battalion, from 1890; however, the training courses for the obsolete Gardner and Nordenfelt Machine Guns continued until 1894. Even so, it was still the case that not all Infantry Battalions had received their Maxim MG by 1897.
Hobart (1971) identifies that, in 1909, the scale of issue was increased to two guns per Battalion. The Regular Battalions were provided with Mk. IV Tripods, while Territorial Force Battalions were issued with the Infantry Carriage, Mk. III.
An alternative to the Maxim was proposed by Vickers, Sons, and Maxim, (VSM) in the form of the 1906 Light Pattern. This used a corrugated jacket instead of the smooth jacket for water cooling. This meant that the strength required could be obtained but was lighter. It also redesigned some of the smaller components of the gun that reduced weight significantly.
A major development took place with the 1908 Light Pattern Vickers. This inverted the toggle mechanism of the lock which reduced the depth of the breech casing. This resulted in a physically smaller and much lighter weapon. This was adopted by the British Army for trials. It was referred to as the Class 'C'.
It became the Mk. I when it was adopted for British Service. This took place on 26th November 1912 by List of Changes 16217.