This article is a part of a larger research project on historical territories and the Turkic population of Azerbaijan in the South Caucasus, first published in 2015 as a monograph, “Azerbaijan and the Armenian question in the Caucasus” (Азербайджан и армянский вопрос на Кавказе). The author drew upon nearly 300 ancient, medieval, and modern sources describing Azerbaijan’s territories in the Caucasus. This article presents the European and American sources from the 18th and early 19th centuries, describing the territory and the population of Azerbaijan in the Caucasus. The aim of this study is to show the historicity of Azerbaijan in regional politics and international relations during the aforementioned period.