Federation Ambassador class heavy cruiser, Starfleet registry NCC-10532.  Robert Lyon served as second officer of the Horatio from 2347 through 2351.  In 2349, Ensign Blobbin requested the Horatio to be his first dury assignment as intelligence officer.  There he served from 2349 to 2350.  In 2373, Lyon displayed a model of the Horatio in his Flag Officer stateroom aboard the Sovereign Class Maximillian.   The Horatio, under the command of Captain Walker Keel, was destroyed in 2364 near planet Dytallix B, apparently by an unknown alien intelligence that attempted to infiltrate Starfleet Command.  (TNG: "Conspiracy")