On 30 July 1941, in London, Poland and the USSR sign the Sikorski–Mayski agreement — the deal restoring diplomatic relations after Germany’s attack on the Soviet Union and providing for a Polish army on Soviet territory.

The agreement de facto voids the 1939 Soviet–German treaties on Poland, provides amnesty for Polish citizens held in the USSR and military cooperation against Germany.

Signed by Władysław Sikorski and Ivan Mayski amid Operation Barbarossa, it opened the way for Anders’ Army and the evacuation of Poles from the USSR.

Relations later broke (1943) over the Katyn massacre; the agreement nonetheless remains a milestone of the wartime alliance.

For Second World War diplomacy, 30 July 1941 marks the restoration of Poland–USSR ties.

The text is on Avalon / diplomatic archives.

The Sikorski–Mayski agreement of 30 July 1941 remains the reference for Polish–Soviet relations in 1941–1943.

Image: London / WWII; Wikimedia Commons. Cropped to 16:9.

Source consulted: Sikorski-Mayski agreement. Treaty text: Sikorski-Mayski agreement (Avalon).