'Farrier' was a British special forces raid on Mljet island off the coast of German-occupied Yugoslavia (22/24 May 1944).
After it had been decided on 5 May that 'Foothound', the operation planned against Ugljan and Pasman islands in the Adriatic Sea off the Dalmatian coast, should be abandoned in the light of unfavourable intelligence reports about the German strength on Ugljan island, the headquarters of Brigadier T. D. L. Churchill’s 2nd Special Service Brigade, part of Major General R. G. Sturges’s four-brigade Special Service Group, opted instead to undertake another island assault.
The decision fell on Mljet, which was attacked on the day on which 'Foothound' was to have been undertaken. In addition to a small detachment of Yugoslav partisans, Mljet was also the operational area for a US reconnaissance section, and the attack was planned in the light of reports received from these sources, which were ignorant of the operation being planned, about the strength and disposition of the German units on the island. However, one week before the planned assault, the partisans and the US reconnaissance section moved away from the German positions to investigate reports from the local population that the Germans were concealing small ships in sea caves on the western side of the island.
Adverse weather delayed the start of 'Farrier' by two days, and it was during the early hours of 22 May that almost 1,000 commandos, tactically divided into two groups, landed on the south coast of Mljet. There followed an encirclement manoeuvre that closed on the German positions at Babino polje. Here the British forces used loudspeakers to demand surrender, but the Germans were nowhere to be found, either because they had pulled back from their positions or because the commandos, who had no local partisans to guide them, became disoriented in the thick forest of Mljet and arrived somewhere other than Babino polje. There was thus no fighting, although there was some German mortar fire from points which the commandos could not pinpoint.
Exhausted by marching across difficult terrain the night of 23/24 March, the commandos re-embarked and returned to Vis island, nine of their number being reported as missing. A few days later small group of commandos returned to Mljet to search for the missing men, but found only three who had joined forces with the local partisans. Of the other six, one had been killed and five captured by the Germans.