Henry Sweet (1845-1912) began at an early age to teach himself Old English and Old Icelandic. Before going up to Oxford, he spent a year at the University of Heidelberg, studying comparative and Germanic philology, and during his undergraduate career he published an edition of King Alfred’s Pastoral Care. His enthusiasm for philology led him to pursue a career in research and teaching, though he did not hold a university post until in 1901 he was appointed to a new readership in phonetics at Oxford. His work on the sounds of English was first published in 1874, and in this revised version in 1888. The work derived from a monograph ‘on the history of long e and o’, but Sweet’s own further research, as well as that of others, led him to a much broader treatment, including an investigation of dialects and medieval and modern English sounds.