The U.S.S. Indefatigable NCC-1760 was a Starfleet Class One starship of the Constitution class of heavy cruiser, originally constructed as the lead ship of the Indefatigable sub-class in 2268. She was uprated to Endeavour sub-class specifications in 2278 and then uprated again to Levant sub-class specifications in 2284.
She fought in several battles in the Taal Tan Offensive of 2283 and was badly damaged in October of that year. She was dry-docked again for repairs, but in light of the losses sustained by Starfleet during the conflict and the upward spiral in Klingon belligerence the decision was made to proceed with a full uprating to First Rate specifications.