 All forms of collaboration between Chetnik units and the NDH effectively ceased in the early months of 1945 with significant clashes between the two occurring in the area of Lijevče Field.One major Chetnik collaboration with the Axis took place during the "Battle of the Neretva", the final phase of "Case White", known in Yugoslav historiography as the "Fourth Enemy Offensive".In 1942, Partisans forces were on the rise, having established large liberated territories within Bosnia and Herzegovina.