English public schools have long been associated to sports with William Webb Ellis’s invention of rugby on the playing fields of Rugby School in 1823 and the definition of soccer rules made possible by early 1860s fixtures between Westminster and Charterhouse School. Looking at the link between the historic English public schools (Westminster, St Paul’s, Harrow, Eton, Merchant Taylors’, Charterhouse, Rugby, Shrewsbury, Winchester) and sport in the twentieth century, this paper will first focus on the male solidarities created by the schools’ extensive practice of sport. In keeping with the values of Muscular Christianity promoted by Hughes’s Tom Brown’s Schooldays, public school loyalty was indeed supposed to extend from team to house to school and on to the nation. The paper will thus also consider the link between sport and military training in schools on the playing fields of which the battle of Waterloo had once been won, to paraphrase the apocryphal quote attributed to the Duke of Wellington, and in which participation to the Junior Training Corps was most of the time compulsory in the twentieth century. Looking at the link between sport, patriotism and nationalism, the paper will finally assess the influence of two world wars on public schools and suggest that, in part due to the lost generation of the Great War, a new metaphorical reversal would take place in which school sports were once again considered as simple games and the promise of a return to a happier, post-war, normality.