Born in London in 1908, Osbert Lancaster was an English painter, illustrator, cartoonist, theatrical designer and writer. He studied at Lincoln College, Oxford where he graduated with a fourth-class degree in English after an extra year beyond the normal three years of study. Intending a career in law, he failed his bar exams and instead entered the Slade School of Art in London.

In 1939 he became cartoonist at the Daily Express, where he pioneered the pocket cartoon, a single-panel, single-column topical drawing appearing on the front page, since imitated in several British newspapers. In these he sympathetically mocked the British upper classes, personified by his characters William (8th Earl of Littlehampton, formerly Viscount Draynflete) and his wife Maudie. During his Express career Lancaster drew some 10,000 cartoons over a period of 40 years.

During World War II, Lancaster worked in press censorship, then in Greece as a Foreign Office press attaché. During the war years his cartoons provided comic relief from the privations of rationing and bombing raids.

In 1951 Lancaster worked with John Piper on designs for the Festival of Britain. This was followed by stage design work for opera, ballet and theatre including productions at Sadler's Wells and Glyndebourne, among them Frederick Ashton's production of La Fille mal gardée.

He was knighted in 1975 where he became one of only a small number of cartoonists to have received the honour. Apart from his knighthood, Lancaster's honours included a CBE in 1953 and an honorary DLitt from Oxford, as well as honorary degrees from Birmingham (1964), Newcastle upon Tyne (1970), and St Andrews (1974).

Lancaster was the illustrator of many books by other writers, including Noblesse Oblige (London, Hamish Hamilton, 1973, edited by Nancy Mitford, and some editions of C. Northcote Parkinson's books, including Parkinson's Law, its sequel The Law and the Profits, In-laws & Outlaws, and Law of Delay.