In July 1943, based on the structures of the Włodzimierz Wołyński District of the Home Army, a Polish self-defence base "Bielin", also known as the "Bielin Republic", was established. The commander of this extensive and strong base was Jan Wyszomirski "Mirek", a member of the AK underground. From August 1943, a detachment of the Home Army, Lieutenant Władysław Cieśliński "Piotrus", was associated with the self-defence. The base had a developed alarm system and rules for mutual assistance by the crews of neighbouring settlements. In the "Bielin Republic" crowds of refugees from the southern part of the Vladimir district and from the Horochow district found shelter. Bielin's residents provided the refugees with shelter, food and medical care. In Bielin, the forces of the "Osnowa" Grouping of the 27th Volhynian Infantry Division of the AK were concentrating and preparing for the "Storm" action. In the village itself, a supply centre was organised for the division's needs, which included mills, windmills, bakeries, butchers, a coffee roasting plant, warehouses, gunsmith's, shoemaker's, tailor's etc. workshops. Home Army soldiers stationed here fought battles against the Germans and units of the Ukrainian Insurgent Army.

In April 1944, the Germans engaged in a decisive battle with the Home Army grouping in Bielin with the intention of completely liquidating the centre. On 5, 7, 9 and 10 April the village was bombed. As a result, many houses were destroyed, some burnt down, and many people were killed. The Germans drove out from Bielin and its surroundings the partisan units of the "Osnowa" grouping resisting them, and shot a dozen or so men from among the civilian population who had collaborated with the Polish underground.

Soldiers killed in battles against the Ukrainian Insurgent Army and the Germans in 1943 and 1944, as well as civilians (who died mainly as a result of German bombing), were buried in two cemeteries in Bielin - one cemetery was set up in the forest (about 80 soldiers are buried here), and the other by the church (about 30 soldiers are buried here).

The forest cemetery was neglected for many years, but in the 1990s, on the initiative of the 27th WDP AK environment, it was restored; the work was financed by the Council for the Protection of Struggle and Martyrdom Sites. A plaque was placed in the forest cemetery with the inscription: "War cemetery / of soldiers of the 27th Volhynian / Division of the Home Army / in Bielin 1939-1944 / 20 X 1992 Compatriots" and a plaque containing the names of soldiers buried in both cemeteries in Bielin. Engraved on it are the names of 64 soldiers and 16 civilians (5 known by name and 11 NN) who died during the bombing of Bielin.