'AC1' was a British naval undertaking by Admiral Sir Andrew Cunningham’s Mediterranean Fleet in support of British operations by Lieutenant General R. O’Connor’s Western Desert Force near Tobruk on the Mediterranean coast of the Western Desert in the aftermath of 'Compass' (i) (20/24 February 1941).

Together with a number of lighter warships, the light anti-aircraft cruiser Coventry provided escort for the monitor Terror, a force of minesweeping corvettes and a tanker. The object was a gunfire bombardment of Axis dumps and communications along the coast, but on 22 February Terror was slightly damaged by two mines, only just laid by Heinkel He 111 bombers, as she was leaving Benghazi harbour. On the following day the monitor was attacked by three Junkers Ju 88 bombers of Hauptmann Arved Crüger’s II/Lehrgeschwader 1 just after the single Hawker Hurricane fighter flying aerial escort had been forced to return to base to refuel, and suffered serious damage resulting in extensive flooding. Even so, the monitor was able to proceed east toward Alexandria, where she could be repaired, under escort of the corvette Salvia and minesweeper Fareham.

The monitor was still taking in water, however, and as she began to settle her crew were taken off by the two escorting ships before Terror, now too low in the water to be taken in tow, was scuttled off Derna after the crew had transferred to Salvia and Fareham.