The U.S.S. Agincourt NCC-1813 was a Starfleet Class One starship of the Constitution class, originally constructed as part of the Second Rate Tikopai sub-class and later uprated to First Rate Levant sub-class specifications.
Originally to be named Hor, heavy cruiser hull number 1813 was renamed "Agincourt" by special dispensation from the Secretary of the Star Fleet before construction began in 2278. Completed and commissioned 2281, she was only in service for four years before mounting Starfleet losses in both the Taal Tan Offensive and subsequent unrestricted warfare by the Klingons through the mid 2280s dictated the need for more heavy cruiser units of the First Rate.
Agincourt herself was dry-docked in late 2285 for a six-month uprating to the latest heavy cruiser specifications, that of the Levant sub-class already under construction, and was recommissioned in mid 2286.