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 12, 1935, Marshal Józef Piłsudski died. He was buried at Wawel, in the crypt under the Tower of Silver Bells.
Father Jan Cieplak was auxiliary bishop of the Mogilev archdiocese, at that time the largest Roman Catholic archdiocese in the world, covering the whole of Russia up to Sakhalin.
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 23 July 1920, the first ship from Vladivostok with Polish children evacuated from Siberia arrived in Tsuruga, Japan. By 1922, a total of more than 700 kids had arrived in the Land of the Cherry Blossom. Their first stops were the cities of Tsuruga and Osaka.