On May 12, 1970, General Władysław Anders, Commander-in-Chief of the Polish Armed Forces in 1944-1945, died in exile in London.
On May 18, 1944, soldiers of the 2 Polish Corps hung the Polish flag on the ruins of the Monte Cassino monastery.
On 4 July 1928, the founding congress of the Sybiraks' Association was held at the Warsaw University of Technology.
The Union of Soviet Socialist Republics was the first communist state in history. The decision to create it was taken on 30 December 1922.
On 18 March 1921, the treaty ending the Polish-Bolshevik war (the so-called Treaty of Riga) was signed in Riga.
On the night of 6 to 7 July (24/25 June old style) 1866, 5,000 kilometres east of their homeland, a group of January insurgents sent to Baikal for penal labour stirred up a rebellion, disarmed their guards and tried to forge an escape route to Mongolia.
