The 1999 Montreal Convention is the most recent in-force treaty to regulate several important aspects of international air carrier liability in a uniform manner. This book examines in detail to what extent the 1999 Montreal Convention's aim of uniformity has been achieved. To this end, it scrutinizes the exact scope of this aim and analyses the factors that may have prevented it from being fully achieved. It studies the wording of the treaty and its predecessors, their travaux préparatoires, the judicial decisions of numerous civil and common law jurisdictions, as well as various other interpretative tools. Among many others, themes addressed in this study include: exclusivity; the autonomy of terms used; translation issues; accident; bodily injury; damage; delay; consumer rights; the 1969 Vienna Convention on the Law of Treaties; hermeneutics; the Warsaw System; regional air law (including EU Regulation 261/2004); and algorithms. The study also suggests ways to reduce the fragmentation of the 1999 Montreal Convention with a series of directly applicable recommendations, and an analysis of what Artificial Intelligence could mean for the future. This book, which is intended to be practical, is aimed at all lawyers well-versed in aviation law as well as aviation enthusiasts. They will find it a useful tool for interpreting the 1999 Montreal Convention in a manner consistent with its ambition, as well as recent case law from all continents on hot topics.