This book offers a comparative review of the ultra vires doctrine in corporate law. Divided into three main sections, it first provides a brief overview of the historical background and the scope of the ultra vires doctrine. It then analyses the essential features of the doctrine in the common law and civil law traditions across the Western world. Lastly, the book examines the objects clause, procedural aspects, and the mechanism of ratification of such ultra vires acts. The book's comparative approach and global contextualization of the subject matter will be of interest to readers from around the globe, familiarizing them with legal provisions, case law, and recent literature. Although it is primarily intended for scholars in the area of corporate law, it is also a valuable resource for professionals in the field of commercial law who deal with issues related to the capacity of firms and the powers of their directors.