This book's aim is to introduce the main concepts of leading international trade and commercial laws with a view to enable students to work on cross-border issues. Thus, this book will introduce to the basics of International Law, followed by the explanation of the general framework of the WTO and of the more specific EU, as well as guide to the concepts of these International Organisations, emphasising those legal provisions of highlighted importance in practice. The chapter on Company Law addresses the common types of undertakings, including an overview of formal criteria, the ultra-vires-doctrine will be focussed as well as recognition of companies (real seat and incorporation theory), and some supranational companies. Finally, the text will introduce to the principles of Contract Law, considering four perspectives: First, common aspects of laws and courts' opinions on contracts and their interpretation will be reproduced, conceptually valid in the vast majority of States, second, the CISG will be explained briefly, third, the International Commercial Terms will be introduced, and fourth, the Letter of Credit.