Crete (Cretan resistance) World War II in Albania Operation Harling, also known as the Battle of Gorgopotamos (Greek: Μάχη του Γοργοποτάμου) in Greece, was a World War II mission by the British Special Operations Executive (SOE), in cooperation with the Greek Resistance groups EDES and ELAS, which destroyed the heavily guarded Gorgopotamos viaduct in Central Greece on 25 November 1942.

Operation Harling was conceived in late summer 1942 as an effort to stem the flow of supplies through Greece to the German forces under Field Marshal Erwin Rommel in North Africa.

To this end, the Cairo office of the SOE decided to send a sabotage team to cut the railway line connecting Athens with Thessaloniki.

[5][6] The Harling mission's British officers were largely ignorant of the realities on the ground in occupied Greece, or of the precise nature, let alone the strength and political affiliation of the emerging resistance groups.

[5][7] The SOE team numbered thirteen men and was divided into three groups, each including a leader, an interpreter, a sapper and a radio operator.

[12] In the meantime, the main group was being hidden by the local Greeks and constantly moved around the area to prevent their capture by Italian searching parties, while Woodhouse set out to the town of Amfissa to establish contact with Cairo.

[15] From the outset, Zervas was enthusiastic for the mission, but Velouchiotis less so, for the Athens-based leadership of EAM-ELAS still did not appreciate the importance and potential of armed struggle in the countryside, preferring to focus on the cities instead.

[19] After the charges were set and the fuses were lit, the first explosion occurred at 01:30, heavily damaging the central pier and collapsing two spans.

Although its original military objective, the disruption of supplies for Rommel's troops, had been rendered obsolete by the Allied victory at El Alamein, it did display the potential for major guerrilla actions in serving Allied strategic objectives, encouraged SOE to aid the development of resistance movements, and provided a major morale boost for occupied Greece.