Franz I, Duke of Sleswig, was a nobleman who ruled over the duchy of Sleswig in the early 19th century. He was born on July 15, 1800, and became the Duke in 1848. His reign was marked by efforts to modernize the duchy and improve its economy, as well as navigating the complex political landscape of the time. As a member of the House of Schleswig-Holstein, Franz I was part of a lineage that played a significant role in the history of Denmark and Germany. He passed away on March 14, 1863, leaving behind a legacy of governance during a period of change in Europe.