In one possible future timeline, the USS Enterprise (NCC-1701-J) was a Federation starship of unspecified class in operation some time during the 26th century.
The Enterprise-J participated in the pivotal Battle of Procyon V, in which the forces of the Federation (at that point in history included the Klingons and Ithenites) defeated the invasion of the Sphere Builders; transdimensional beings who worked to colonize the galaxy by reconfiguring space. The temporal agent Daniels brought Jonathan Archer from the 22nd century aboard the Enterprise-J to witness the battle; so that he might convince Archer of the need to make peace between the Xindi and the Humans of the 22nd century. The crew of Enterprise-J included several Xindi, one of which owned a medal that Archer used to help convince Degra that he wanted peace.