Maxim gun

The Maxim gun was the first self-powered machine gun, invented by the American-born British inventor Sir Hiram Stevens Maxim in 1884. It has been called "the weapon most associated with 'British' imperial conquest"

Maxim gun in Southern Victory
The Maxim gun was employed by all the great armies of the world. Although they built their own versions of it, it was universally called 'Maxims' by all who used them. They were the most prolific killers of the war, and those who operated them found it extremely difficult, if not impossible, to surrender once they'd been captured.

As the war progressed and newer, more powerful machine guns were developed, the name was dropped by the way side.