This publication is devoted to the natural feature - the Black Sea and its littoral states. At the same time the Azov Sea is also considered here. This region is the focus of many geopolitical, economic, social and environmental issues that involve not only the countries coming out to the Black and Azov Seas, but other world countries, too. This publication contains over 1500 articles and terms providing descriptions of geographical and oceanographic features, cities, ports, transport routes, marine biological resources, international treaties, national and international programs, research institutions, historical and archaeological monuments, activities of prominent scientists, researchers, travelers, military commanders, etc. who had relation to the Black Sea. It includes a multi-century chronology of the events that became the outstanding milestones in the history of development of the Black Sea - Azov Sea region. .