The USS Horatio Nelson was a Starfleet frigate during the late-24th century. It was a part of a fleet that won the decisive Battle of Sector 21505 in the final days of the Federation-Cardassian border conflict. Its crew discovered that the automated Cardassian dreadnaught running kamikaze maneuvers at the Federation fleet was controlled by a single Galor-class warship. Following the Klingon invasion of the Cardassian Union, the Horatio Nelson was again assigned to Cardassian space