Walter Carruthers Sellar was a Scottish humourist who wrote for Punch. He is best known for the 1930 book 1066 and All That, a tongue-in-cheek guide to "all the history you can remember," which he wrote together with R. J. Yeatman.
Sellar was born at Golspie in Sutherland. He won a scholarship to Fettes College where he was Head Boy in 1917. After serving briefly in World War I as a Second Lieutenant in the King's Own Scottish Borderers, he took a degree in modern history at Oriel College, Oxford (which, as recorded in 1066 and All That, was awarded through an aegrotat in 1922). It was at Oriel that he met his contemporary Yeatman, and struck up a lifelong friendship. Although the two produced brilliant work together, they were entirely different personalities: Sellar was somewhat shy and introverted, although he enjoyed acting. He wrote melancholy poetry in addition to dry humour.
Sellar had begun to contribute to Punch in 1925 when three humorous short stories of his were published (he also contributed to other journals around this time). His collaboration with his old University colleague Yeatman, who was also writing for Punch, appears to have begun in 1928 during his period out of teaching. The first part of 1066 and All That appeared in Punch on September 10, 1930, taking its title from Robert Graves' autobiography Good-Bye to All That. Sellar's contribution is particularly noted in the comic exaggerations and name confusions; his knowledge of English literature also inspired the book's many literary allusions and pastiches.
After completing the book, Sellar worked with Yeatman again on a sequel, And now all this, a parody of general knowledge, including subjects as diverse as geography, knitting and topology, which is relatively little remembered. The 1933 book Horse Nonsense was credited to the two but is largely the work of Yeatman, while Garden Rubbish and other Country Bumps is also credited to the two but largely Sellar's work. It is noted for a more nuanced form of humour which depends on elaborate word-play.