Henry I, Duke of Guise (1519-1563), was a prominent French nobleman and military leader during the French Wars of Religion. He was a member of the powerful House of Guise, known for its staunch Catholicism and opposition to Protestantism. Henry played a significant role in the conflicts between Catholics and Huguenots, leading troops in several key battles. As a member of the royal family, Henry sought to expand his influence and power. His ambitions led to political intrigue, including his involvement in the assassination of Admiral Gaspard de Coligny, a leading Protestant figure. Ultimately, Henry's life ended violently when he was assassinated in 1563, marking a significant moment in the ongoing religious strife in France.