The early years of the war were relatively quiet in Friesland, with only incidental acts of resistance. This changed after the May Strike of 1943. The cause was the German occupier's call for all Dutch prisoners of war released in 1940 to be put to work in Germany. This triggered the resistance in Friesland to become better organised. Existing groups were merged into the Dutch Internal Armed Forces (NBS), which were founded in Friesland on 12 December 1944 on the orders and under the leadership of Prince Bernhard.

In Makkum, the resistance was active from the very beginning of the war. The brothers Aart and Thymen van den Berg made their fish canning factory entirely available to the Frisian resistance. Using the weapons, alcohol and smoked eel, the staff of the factory became friends with the most important executioners of the Sicherheitsdienst in Leeuwarden. When the Germans were loosened up by the drinks, the information they spilt was passed on to the resistance. They managed to free 60 imprisoned resistance fighters and knew when to expect raids. The fish canning factory grew to be a hotbed of Frisian resistance. The Sicherheitsdienst in the Burmania house in Leeuwarden was bugged, and the resistance was able to warn people named in interrogations. Other forms of resistance were the distribution of illegal magazines to inform the population about troop relocations, collaborators, or to boost morale.

In the summer of 1943, there was a wave of people going into hiding, and the expansive Frisian countryside proved to be very suitable for sheltering people. The resistance also played an important role here. Thugs raided distribution offices and stole huge quantities of food stamps, for example. Towards the end of the war, there was a food shortage and dairy factories, butchers and food producers were targeted. During this period, the first arms droppings like the ones on Kornwerderzand took place. On 13 April 1945, the NBS leadership followed the order to help accelerate the advance of the allied troops. Large parts of Friesland were liberated in Mid-April 1945.