Killed in action atGallipoli in the Dardanelles Campaign of 1915, aged just twenty-seven, Henry Gwyn JeffreysMoseley was widely regarded as the most promising British physicist of hisgeneration. His pioneering measurements of X-ray spectra provided a firm basis forthe concept of atomic numberand re-cast the periodic table of the elements into its modern form. Had he survived, he seemeddestined to win a Nobel Prize.This book is acommemoration of Moseley’s life, work, and legacy. Inspired by the exhibition ‘DearHarry… Henry Moseley: A Scientist Lost to War’, at the Museum of theHistory of Science, Oxford, in 2015-2016, and revisiting earlier accounts,thirteen historians and scientists chart his experience of Manchester andOxford; his military service; the reception of his work by the scientificcommunity; and the impact of his work upon X-ray spectroscopy in physics,chemistry, and materials science. For Science, King &Country speaks to those with an interest in history, science, and theFirst World War, and draws upona wealth of archives, artefacts, and recent research on the reward systems of science.Overall, it presents a comprehensive account of a young scientistwhose brief but mercurial careerpaved the way to a new understanding of nature, and to shaping the future of physicalscience.