It was conducted by the British Special Boat Service, against the mixed German and Italian garrison on the island of Santorini (Thera) in the Aegean Sea.

The British wished to maintain a secondary front in the Aegean, therefore, after the fall of Kos and Leros, the Middle East HQ issued orders to the SBS special forces unit to attack the garrisons of occupied Greek islands such as Santorini.

[3] On April 19, a group of 19 commandos under Major Anders Lassen sailed from their hideout in Balisu bay, Turkey aboard two schooners.

After a three-day voyage that included intermediate stops in Syrna and Anydros, the group landed on an easterly beach near cape Columbo on the night of 22 to 23.

It has been claimed that this was the result of a letter written to Lt Hesse by Lassen, warning him that his name was known to the Allies who would hold him accountable for any reprisals he ordered.

Another 13 civilians from Imerovigli who were hoping to sack German provisions in the radio building died when the explosives installed in it went off.

[2] This and similar operations forced the German General Kleemann to instruct his troops that "[they were] living in an enemy country"[2] and reinforce the Aegean garrisons by 4,000 men.