King's nickname is taken from a gimlet, a tool used for drilling small holes - and hence the term "gimlet-eyed", meaning someone with piercing eyes and keen vision.
The rest of the name may have been inspired by South African soldier and adventurer William Lorraine King who died shortly before the first novel was published.
His regular comrades are Corporal Albert "Copper" Edward Collson (an ex-policeman), Private "Trapper" Troublay, and Nigel Norman "Cub" Peters.
Gimlet and his team of commandos were designed to represent the multiple ethnicities of the British Empire; along with the English characters, French-Canadian, Scots, and European-educated Asians co-operate for the good of Britain.
In later stories, Gimlet seeks treasure, and must work as both hunter and prey when Werwolf terrorists try to exact revenge on those they call British "war criminals".