Educated at the Hugh Myddleton School in Islington, aged 14 he was the London Junior Boxing Champion; later, he followed his father into working for the General Post Office (GPO) before serving with the Coldstream Guards during World War I.

[2] A completely self-taught cartoonist, around 1920 Minnitt began to contribute single joke cartoons to the comics of the Amalgamated Press (AP).

Subsequently, his work appeared in various titles including Comic Life, Joker, Merry & Bright, Butterfly, Jolly and Sparkler.

It was an entirely different Greyfriars School from that described by Charles Hamilton in The Magnet but it became immediately popular, with Minnitt continuing to draw Bunter until shortly before he died in 1958.

In the mid to late 1940s his work appeared in a number of different short-run titles issued by small publishers; these included Comicolour, Jingo, Swell Comic, Big Laugh, and various others.