The Duchess was finished around the same time as the UNSC Setback. The ship was sent to Earth when the Covenant launched a second assault on the planet, and throughout the crew's skill and the ships fast speed did it survive the following ferocious battle. The Duchess, like the Setback, was meant at first to be part of the UNSC 19th Fleet, but was attached to Battlegroup Kilo after the end of the war and has continued to faithfully serve the Battlegroup ever since. It is commanded by Captain Webb Washington.