After the death of Prime Minister Sikorski, the important figures in the exile government in London were President Władysław Raczkiewicz, the newly nominated Prime Minister Stanisław Mikołajczyk and Commander-in-chief Kazimierz Sosnkowski. During the Tehran Conference (November–December 1943) Stalin, Franklin D. Roosevelt and Winston Churchill determined the geographic location of the future Polish state (between the Oder River and the Curzon Line) without consulting or even notifying the Polish leaders. Czechoslovakia, previously Poland's partner for a planned confederation, signed in December 1943 a friendship treaty with the Soviet Union. As a result of the developing Soviet wartime advantage, the Polish government was gradually abandoned by its allies.
