The article discusses the historical geography of the river Prut (967 km). In the ancient period it was known as the Pyretus, Porata, or Prout. The river originates on the eastern slope of Mount Hoverla (2 068 m), in the Carpathian Mountains in Ukraine. The Prut flows to the southeast, eventually joining the Danube near Giurgiuleşti, east of Galați. The Prut currently divides three countries: Romania, the Republic of Moldova and Ukraine. At present, it constitutes the border between Romania and Moldova, with a total length of 695 km. It has a hydrographic basin totaling 27 540 km2, of which 10 990 km2 are in Romania and 7 980 km2 in Moldova. The article presents a summary description of the geographical setting and hydrographic specificity of the Prut River. The main geo-morphological characteristic features of the Prut basin are presented. The author also offers a historical overview of the main settlements situated on the river, as well as a brief analysis of the recent projects for international cooperation centered on the Prut as an important waterway of the region. Finally, the author emphasizes the role of the Prut as a border river, looking at both the pragmatic and symbolic dimensions of its significance for Romanian history.