(written from a Production point of view)
USS Endeavour was a Federation starship in the alternate reality mentioned in the the script of Star Trek. In the script, Cadet Jaxa was assigned to the Endeavour in Hangar 1, when the ship was launched to respond to the attack on Vulcan by the Narada in 2258.
In Issue 1 of the Star Trek: Boldly Go comic series, the issue revealed that the ship had a registry of NCC-1805 and was commanded by Derbes (β) before he retired in 2263. Following the attack on Starbase Yorktown, James T. Kirk, was given temporary command of the Endeavour for one year while the USS Enterprise-A was being built.