Admiral Thomas Edward Theisman is a fictional character in the Honorverse, a series of military science fiction novels written by David Weber. He first appeared as a starship commander in The Honor of the Queen, the series' second novel, and gradually became one of the leading antagonists of the series. Thomas Theisman was born on Haven to an unmarried Dolist teenager whom he never knew, and spent his childhood in a state-run créche. He joined the People's Navy immediately after high school.