The Forest Brothers (Estonian: metsavennad) were the Estonian partisans who waged guerrilla warfare against Soviet rule during the Soviet invasion and occupation of the three Baltic states during, and after, World War II.
The Red Army occupied formerly independent Estonia in 1940–1941 and, after a period of occupation of Estonia by Nazi Germany, again in 1944–1945. As Stalinist repression intensified over the following years, thousands of residents of this country used the heavily-forested countryside as a natural refuge and basis for armed anti-Soviet resistance.
Resistance units varied in size and composition, ranging from individually operating guerrillas, armed primarily for self-defence, to large and well-organised groups able to engage significant Soviet forces in battle.
By the late 1940s and early 1950s the Forest Brothers were provided with supplies, liaison officers and logistical coordination by the British (MI6), American, and Swedish secret intelligence services. This support played a key role in directing the Baltic resistance movement, however it diminished significantly after MI6's Operation Jungle was severely compromised by the activities of British spies (Kim Philby and others) who forwarded information to the Soviets, enabling the KGB to identify, infiltrate and eliminate many Baltic guerrilla units and cut others off from any further contact with Western intelligence operatives.
The conflict between the Soviet armed forces and the Forest Brothers lasted over a decade and cost at least 50,000 lives. Estimates for the number of fighters in each country vary. Misiunas and Taagepera estimate that figures reached between 10,000 and 15,000 in Latvia and 170,000 for Estonia, Latvia, and Lithuania combined. Investigation of newly-opened Soviet archives by Baltic historians in the 1990s showed evidence that NKVD units dressed as forest brothers and committed atrocities in order to demoralize the civilian population.
In Estonia total 14,000 - 15,000 men participated in fighting during 1944-1953. Estonian Forest Brothers were most active in Võru County and border areas between Pärnu County and Lääne County, and between Tartu County and Viru County. During period November 1944 - November 1947 they made 773 armed attacks and killed about 1000 Soviets and their supporters. August Sabbe, the last surviving Forest Brother in Estonia, was discovered by KGB agents in 1978, he was posing as a fisherman. Instead of surrendering, he jumped into a river and hooked himself to a log, drowning.