Thomas Hughes's idealised vision of life at Rugby public school is one of the best-known novels in the English language. It was regarded from the outset as a founding text of 'muscular Christianity'. Contrary to the intentions of its author, it helped to inaugurate the cult of 'manly' athleticism that swept through the English public schools in the second half of the nineteenth-century. I argue that the novel reveals tensions around gender and sexuality that were in play among public schoolboys during the second half of the nineteenth century. These tensions exploded into full public view in the trial of Oscar Wilde in 1895 and were instrumental in helping to establish a structure of homophobia within homosocial settings that has lasted through to the present day.