This book offers a comprehensive introduction to Proto-Indo-European, Balto-Slavic and Proto-Slavic accentology; a branch of diachronic linguistics dealing with the development of syllable stress, intonation, and quantity at the word level. Of particular interest in the book is its detailed summary of the major approaches and solutions to accentology of the last thirty years.Furthermore, the book provides a comprehensive overview of the current state of research on accentuation of the Indo-European proto-language and the accentuation of Balto-Slavic languages. Such research is integral to our knowledge of how accentual patterns developed from the reconstructed proto-language to the modern Indo-European languages.