'Manacle' was a British series of special forces raids by 'Layforce' (in its second iteration) and an extemporised unit formed by the French Troop of No. 10 (Inter-Allied) Commando and three troops of No. 4 Commando (December 1943/January 1944).
The object of the raids was to destroy German strongpoints along the coast of German-occupied France and at the same time undertake beach reconnaissances. No. 4 Commando participated in 'Manacle 5' at Quival and 'Manacle 8' at Quend Plage, both raids being launched from Dover. The 'Manacle' and associated 'Hardtack' raids were finally abandoned by the Combined Operations Headquarters after it had come to be appreciated that they encouraged the Germans to reinforce their positions, a fact which, in the longer term, would be disadvantageous to the Allies when 'Neptune' (iii) 'Overlord' were launched.