Duke Francis William was a member of the House of Habsburg, born in 1620. He was the son of Duke Leopold V and Clara of Austria. Francis William held the title of Duke of Saxe-Lauenburg and was known for his involvement in the political affairs of his time. He played a significant role in the Thirty Years' War, which lasted from 1618 to 1648, impacting much of Europe. Francis William's contributions to the war and his noble lineage made him a notable figure in European history, particularly within the context of the Habsburg dynasty.