The Battle of Brześć Litewski (also known as the Siege of Brześć, Battle of Brest-Litovsk or simply Battle of Brześć) was a World War II battle involving German and Polish forces that took place between 14 and 17 September 1939, near the town of Brześć Litewski (now Brest, Belarus). After three days of heavy fights for the stronghold in the town of Brześć, the Germans captured the fortress and the Poles withdrew. History Before the battle Initially, the Polish forces did not plan to defend the old fortress of Brześć. The town was located deep behind the Polish lines and was seen as a supply depot and organisation centre rather than a front-line fort. However, after the Battles of Mława and Wizna the German XIX Panzer Corps under General Heinz Guderian broke through Polish lines and sped southward with the aim of flanking Warsaw from the East and cutting Poland in two. According to the secret protocol of the Molotov–Ribbentrop Pact of 23 August 1939, the region of Brześć was assigned to the Soviet "sphere of influence". However, the Soviets did not begin their invasion of Poland yet, and had the rapidly advancing German corps stopped, it would give Poles time to regroup and prepare. Already on 8 September the German foreign minister, Joachim von Ribbentrop, notified the Soviet government that the German forces would have to violate the Soviet "sphere". The ancient fortress of Brześć is at the confluence of Muchawiec and Bug Rivers. Occupying the site of a medieval castle, it was strengthened and reconstructed in Napoleonic times and then again in 1847. Heavily damaged during World War I, the fortress was turned into a matériel depot and its central part into a prison. Although largely obsolete by contemporary standards, the fortress occupied a strategic position in the Polish lines and its defence could prevent German forces from crossing Polesia into Lesser Poland and Galicia to the south. The aim of the German XIX Corps was to seize the fortress in order to prevent elements of a divided Independent Operational Group Narew under General Młot-Fijałkowski from retreating southwards and joining the rest of the Polish forces. The German forces consisted of an entire armoured corps: the 3rd Panzer, 2nd Motorised and 20th Motorised Divisions. At the end of the summer the fortress was housing the march battalions of 82nd and 35th infantry regiments and elements of various smaller