A history of conservation of religious monuments in GDR -- churches, cathedrals and cloisters -- which, aside from natural deterioration, suffered fire damage or damage due to negligence, not to mention serious damage from battles and bombs during the Second World War. Many buildings collapsed. Substantial restoration works have been undertaken: repair, reinforcement, reassembly of stained-glass windows, resurfacing and painting of facades, restoration of frescoes and total reconstruction. In the past four decades the theoretical approach of this restoration work has changed: priority is now assigned to giving a building its original style. It thus becomes a useful documentary source for scientific, historical and artistic research into its period of construction. -- AATA