The Kennedy class of United Federation of Planets diplomatic cruisers were active in the 23rd and 24th centuries. (Starbase 79: Starship Recognition Series 2) The Kennedys were a purpose-built class (similar in superstructure to the Surya-class) developed to provide a safe environment for treaty negotiations and conflict resolution. Defensive systems were enhanced and weapons systems were designed to be as unobtrusive as possible. In a break from Starfleet tradition, captains were chosen from the ranks of the Federation Diplomatic Corps, and not Starfleet.