Sikorski–Mayski agreement

[1][2][3] Its name is taken from its two most notable signatories: the prime minister of Poland, Władysław Sikorski, and the Soviet ambassador to the United Kingdom, Ivan Mayski.

Strongly encouraged by British Foreign Secretary Anthony Eden, Sikorski on 5 July 1941[2][3] opened negotiations with the Soviet ambassador to London, Ivan Mayski, to re-establish diplomatic relations between Poland and the Soviet Union.

[5][6] Later that year, Sikorski went to Moscow with a diplomatic mission[7] (including the future Polish ambassador to Moscow, Stanisław Kot, and the chief of the Polish Military Mission in the Soviet Union, General Zygmunt Szyszko-Bohusz).

Stalin agreed to declare all previous pacts that he had with Nazi Germany null and void, to invalidate the September 1939 partition of Poland and to release tens of thousands of Polish prisoners-of-war held in Soviet camps.

The whereabouts of thousands more Polish officers, however, would remain unknown for two more years and weigh heavily on subsequent Polish-Soviet relations.