Admiral Sir William Cornwallis, was a Royal Navy officer. He was the brother of Charles Cornwallis, 1st Marquess Cornwallis, British commander at the siege of Yorktown. Cornwallis took part in a number of decisive battles including the siege of Louisbourg in 1758, when he was 14, and the Battle of the Saintes but is best known as a friend of Lord Nelson and as the commander-in-chief of the Channel Fleet during the Napoleonic Wars. He is depicted in the Horatio Hornblower novel, Hornblower and the Hotspur.

Charles Cornwallis, 1st Marquess Cornwallis, KG, PC was a British Army officer, Whig politician and colonial administrator. In the United States and the United Kingdom, he is best known as one of the leading British general officers in the American War of Independence. His surrender in 1781 to a combined American and French force at the siege of Yorktown ended significant hostilities in North America. Cornwallis later served as a civil and military governor in Ireland, where he helped bring about the Act of Union; and in India, where he helped enact the Cornwallis Code and the Permanent Settlement.