The rise of investment arbitration in the last decade has generated an unprecedented body of arbitral case law. The work of these arbitral tribunals has provided scholars and practitioners with public international law jurisprudence, including materials on treaty interpretation which has not yet been thoroughly analysed. This book evaluates the contribution of investment arbitration treaty interpretation jurisprudence to international law, covering all key aspects of treaty interpretation. Included in the book's coverage are awards which feature in prominent discussions or in applications of treaty interpretation rules. Among the significant portion of arbitral awards analysed, which deal with investment treaties, are ICSID awards, ad hoc investment arbitration awards, NAFTA awards, and Energy Charter Treaty awards. The extensive analysis of investment arbitration awards and decisions has also been used to create a table highlighting both the references to principles of treaty interpretation and instances in which they were rejected. This invaluable insight into the practice of investment tribunals will be of interest to both practitioners and academics alike. Foreword by by Professor Michael Reisman, Yale Law School _