Named "dark" due to its hull's dark shark gray, nearly black, color, the Dark Starship was stolen from an alternate universe by Samantha Delaney and her followers. She outfitted the ship with a folded space drive prototype, allowing it to travel through time and space.
With the prototype installed, the ship also was outside of normal space-time, protecting it from conventional weaponry.
In 2361, the Dark Starship confronted the USS Cartwright and severely damaged the Cartwright, dragging it forward in time. The Cartwright, severely damaged, separated the ship, allowing the saucer section to crash on the planet's surface. (Star Trek: The Cantabrian Expeditions: "Bitter Sweet")
In 2373, Elizabeth Singh, aboard a runabout from Deep Space 4, was sent into an alternate reality by the Dark Starship. Limited sensor data was gathered by the surviving crew aboard the runabout. (Star Trek: The Cantabrian Expeditions: "Stranger Than Fiction")
Helena Bourget was taken aboard the Dark Starship as a member of her crew. (Star Trek: The Cantabrian Expeditions: "She Woke Up Screaming Aloud, A Prayer From Her Secret God")
The USS Cantabrian tracked down the Dark Starship and fought in a cat-and-mouse battle with it, finally cornering it with the help of the Aotearoa. With two options -- let the Dark Starship go and save his crew, or take out the Dark Starship and his ship at the same time -- Captain Noah Wrightson decided to take out the Dark Starship, but Delaney had a different plan, firing the Dark Starship's temporal weapon and throwing the Aotearoa to a different space-time. (Star Trek: The Cantabrian Expeditions: "Best Served Cold")
The cat-and-mouse game heated up and came to a head in late 2373 when Delaney pushed the Dark Starship into the heart of the Federation. With several starships taking the Dark Starship on and losing, the Dark Starship forced its way to Earth. The Cantabrian took out the folded space drive by crashing into the ship, bringing the Dark Starship into phase with normal space-time. With an away team led by Wrightson boarding the Dark Starship, they captured the ship and Delaney, but not without sacrifice: in order to stop the temporal weapon from firing at Earth, Wrightson threw himself into the temporal stream. (Star Trek: The Cantabrian Expeditions: "By All Means Necessary")
The Starfleet Corp of Engineers took control of the Dark Starship to research its technology.