In 1876 the Leipzig publisher Breitkopf und Hartel launched a series on Indo-European languages entitled 'Bibliothek Indogermanischer Grammatiken'. The first three volumes covered phonology, Greek and Sanskrit. This short introduction to the comparative method, published in 1880, was the fourth. It was highly successful, with six editions appearing between 1880 and 1919. Its author, Berthold Delbruck (1842-1922), Professor of Sanskrit at Jena, was a former student of the pioneering Indo-Europeanist Franz Bopp. Delbruck expanded the horizons of the field to cover syntax as well as phonology and morphology; his magisterial studies of Sanskrit and Indo-European syntax (also reissued in the Cambridge Library Collection) appeared between 1886 and 1900. This book, designed as a guide for readers of the Breitkopf series, includes a fascinating history of Indo-European philology from its founding fathers Jones and Bopp through Humboldt, Schleicher and Curtius to Delbruck's own time, and outlines the most recent developments.