The Battle of Mława, otherwise known as the Defence of the Mława position, took place to the north of the town of Mława in northern Poland between 1 and 3 September 1939. It was one of the opening battles of the Invasion of Poland and World War II in general. It was fought between the forces of the Polish Modlin Army under General Krukowicz-Przedrzymirski and the German 3rd Army under General Georg von Küchler.
History
Eve of the Battle
As a result of the Treaty of Versailles, the new German-Polish border was located only some 120 km north of Warsaw, the Polish capital city. In 1939 the Polish Modlin Army, led by Brigadier General Emil Krukowicz-Przedrzymirski, was thought of as the main defensive force guarding Polish borders from the north. It was located along the border with East Prussia and was to stop the enemy forces advancing towards Warsaw, the Modlin Fortress. Shortly before the war, a decision was made to strengthen the Polish defences by construction of a line of field fortifications and concrete bunkers to the north of Mława, in the centre of the army's positions.
The main line of defence of the army was located along the line of Narew and Vistula rivers. There were a number of 19th-century fortifications in the area, but the plains to the north of it were almost defenseless. To ease the delaying actions in case of a war with Germany, the Polish General Staff decided that the Modlin Army should be transported to the border with East Prussia and should defend the line for as long as possible. Afterwards, the units under command of General Przedrzymirski-Krukowicz were to withdraw to the south and defend the line of Narew and Vistula rivers, together with the forces of Narew Independent Operational Group.
After the Polish secret mobilization had started in March 1939, the 20th Infantry Division was assigned to the Modlin Army and transported to the area of Mława. In addition, the army commander was assigned a number of trainloads of concrete and other construction materials and several combat engineering battalions. It was decided that a line of fortifications should be constructed in the area held by that division. On 19 June that year the project was ready and was finally approved by Marshal of Poland Edward Rydz-Śmigły on 3 July.
The line of trenches and concrete bunkers, shielded by anti-tank trenches and obstacles, was to be constructed along a low glacial hill overlooking the valley of the Mławka river, to the north of the town. The river itself could be blocked by a dam to enhance the defensive capability of the area. In the center, the swampy terrain of the Niemyje Marshes was located, which was virtually impassable to enemy armored vehicles. This swamp divided the area into two separate flanks. The western section was to be reinforced with 68 concrete bunkers while the eastern, much shorter, with 25.
In peacetime the 20th Division was located in Baranowicze. In case of a war with the USSR, it was planned as the first-line unit to defend a line of German World War I fortifications built there in 1915. Because of that, most of its soldiers had experience in defending fortified positions.
The construction of bunkers in the western section of the front, near the town of Mława, was started on 14 July. It was carried out mostly by the soldiers themselves, under the command of the head of the 20th engineering battalion, Maj. Juliusz Levittoux. The construction of the eastern flank bunkers near the village of Rzęgnowo started on 12 August. Soon the soldiers were joined by a number of civilian volunteers, helping to dig the trenches. However, the positions were not finished until the outbreak of World War II and many of the bunkers were not completed.