On November 28th 1943 there was the Tripartite Dinner Meeting of the Tehran Conference.
The conference, which was codenamed Eureka and was to last from November 28th until December 1st, was held in Tehran, Iran, in the Soviet Embassy, and was between the leaders of the Big Three Allied powers - Winston Churchill of the United Kingdom, Joseph Stalin of the Soviet Union and Franklin D. Roosevelt of the United States.
The main aim of the conference was the opening of a second front against Nazi Germany and this was agreed to, despite the differences between the leaders. There were multiple other issues discussed, including Imperial Japan and a promise for Iran's independence.
Image: See page for author [Public domain], via Wikimedia Commons (commons.wikimedia.org/wiki/File:Tehran_Conference,_1943.jpg)