Around the middle of the 2nd millennium B.C., after the end of the first Babylonian dynasty, there is a chronological gap in all of our information from Mesopotamia, the Dark Age, which makes it impossible to establish the absolute chronology of the earlier half of the millennium and before. Only relative dates can be provided prior to c.1430/1420 B.C. The central problem of Mesopotamian chronology is the dating of the first Babylonian dynasty. Attempts have been made to compute an absolute date for this dynasty by means of the “Venus Tablet” written, it would seem, during the reign of the Old Babylonian King Ammisaduqa. But the data in the table is difficult to interpret and has resulted in three chronologies, the high, the middle and the low. This “introduction” to the chronology of 2nd millennium Mesopotamia includes the topics which form the basis for chronological discussions, such as the dating methods and calendars of Mesopotamia, relevant sources for Mesopotamian chronology and natural science information. Each chronological topic is discussed in a separate chapter. The topics, hence chapters, are arranged alphabetically, not in order of importance: the chronological importance of each topic is considered in a summary at the end of each chapter. Chapter 1 starts with an overview of the problems of 2nd millennium Mesopotamian chronology. Throughout the book previous research in the individual topics is reviewed at some length with constant reference to the relevant publications and related topics. This book is not an argument for any of the currently proposed chronologies, but an extensive and critical review of existing studies. It is hoped that it will offer insights into the current state of chronological research in Ancient Near Eastern studies and will stimulate further research.