Raymond John Chambers was born just over a century ago on 16 November 1917. It is more than fifty years since his first classic, Accounting, Evaluation and Economic Behavior, was published, more than forty since Securities and Obscurities: Reform of the Law of Company Accounts (republished in 1980 as Accounting in Disarray) and over twenty since the unique An Accounting Thesaurus: Five Hundred Years of Accounting. They are drawn upon extensively in this biography of Chambers’ intellectual contributions, as are other of his published works. Importantly, we also analyze archival correspondence not previously examined. While Chambers provided several bibliographical summaries of his work, without the benefits of reviewing and interspersing the text with correspondence materials from the Chambers Archive this study would lack an appreciation of the impact of his early childhood, and nuances related to his practical (including numerous consultancies) and academic experiences. The ‘semi-biographical narrative’ codifies article and editorial length exercises by the authors drawing on parts of the archive related to theory development, measurement and communication. Other parts are also examined. This allows us to respond to those critics who claim his reforms were naive. They further reveal a man of theory and practice, whose theoretical ideas were solidly grounded on observations from his myriad interests and experiences. Many of his practical experiences have not been examined previously. This approach and the first book-length biography differentiates this work from earlier analyses of Chambers’ contribution to the accounting literature. American Accounting Association’s 2021 Thomas J. Burns Biographical Research Award winner, this book provides evidence to support the continued push for the reforms he proposed to accepted accounting thought and practice to ensure accounting is the serviceable technology so admired by Pacioli, Da Vinci and many other Renaissance pioneers. It will be of interest to researchers, educators, practitioners and regulators alike.