Karl Aitschuler was a Manticoran citizen and an officer of the Royal Manticoran Navy.
At the Royal Manticoran Naval Academy, he was in Admiral Honor Harrington's Introductory Tactics class, and earned three invitations to dinner at the Bay House. During the dinner, he carefully positioned himself so that fellow cadet Abigail Hearns would sit between him and the Admiral. After graduating, he went on his midshipman cruise aboard the heavy cruiser HMS Gauntlet and participated in the Battle of Tiberian. (HHA4.6: TSotS)