Leopold Joseph von Daun, also known as Leopold Joseph Daun, Count of Thiano (German: Leopold Joseph Graf Daun, Freiherr von Thiano; Hungarian: Daun Lipót József gróf; 25 September 1705 – 5 February 1766), was an Austrian military leader and Marshal of the Holy Roman Empire. Born into a noble family of Italian origin, Daun served in the Habsburg military and rose to prominence during the War of the Austrian Succession and the Seven Years' War. He is particularly noted for his victories against the Prussian forces led by Frederick the Great, most notably at the Battle of Kolín in 1757, which halted Frederick's advance into Bohemia. Daun's strategic acumen and defensive tactics were highly regarded, and he played a crucial role in maintaining Habsburg control over key territories during these conflicts. His legacy endures as one of the most capable military commanders of the 18th century.