The Ernestine Line is a historical boundary that marked the division between the territories of the Ernestine branch of the House of Wettin and other noble families in Germany during the late Middle Ages. This line was significant in the context of the political landscape of the region, influencing territorial claims and governance. The line emerged after the division of the Wettin lands in the early 16th century, leading to the establishment of various Ernestine duchies. These duchies included notable regions such as Saxony and Thuringia, which played important roles in the cultural and political development of Germany.