The Duchy of Schleswig was a historical region located in what is now southern Denmark and northern Germany. It was part of the larger Duchy of Slesvig and was ruled by various Danish and German noble families over the centuries. The duchy played a significant role in the conflicts between Denmark and Germany, particularly during the 19th century. In 1864, the Second Schleswig War led to the annexation of Schleswig by Prussia and Austria, marking a pivotal moment in the region's history. The duchy was later fully integrated into the German Empire in 1871, which further solidified its German identity and influence.