This book investigates the structure and historical development of the Old Prussian language. William R. Schmalstieg, a renowned historical linguist, presents a comprehensive grammatical analysis based on existing textual evidence and comparative linguistic methods. The work aims to provide a foundational understanding of Old Prussian's phonology, morphology, syntax, and lexicon, situating it within the broader context of Baltic and Slavic languages.

This work is recognized as a significant scholarly contribution to the study of Baltic historical linguistics. Its detailed grammatical framework and reliance on primary linguistic data establish it as a key reference for specialists in the field. The book's rigorous approach and comprehensive scope make it an authoritative resource for understanding the complexities of Old Prussian.