On the heels of the Allied victory in Tunisia, British Prime Minister arrived in Washington on May 12, 1943 for a meeting with President Roosevelt known as the Trident Conference. The Allies' position in the war had changed dramatically since Churchill had visited Washington in December of 1941. He made reference to the Allies' long struggle in an address to a joint session of Congress during his visit. The relationship between the Allies had altered significantly, and the US became the leading partner.