A comparative study of memoirs and documentary sources pertaining to the Tehran Conference allows the author to challenge and correct some of the prevalent positions held within both historiography and popular literature on the subject. In contrast with the pervasive assumption regarding the stance of the “Big Three” on the matter of the Second Front (Stalin and Roosevelt were proponents of an expeditious invasion of Normandy, in contrast to Churchill’s ‘Mediterranean-Balkan’ strategy), he demonstrates that the US President, ostensibly under the influence of his military advisers, was initially amenable to supporting British plans. It was only through the persistent efforts of Soviet diplomacy that the American leader was persuaded to join Stalin in prioritising Operation Overlord. The real breakthrough on the Second Front issue occurred during and after an informal dinner hosted by Roosevelt after the first session of the conference on 28 November 1943, which was earlier than had previously been asserted. In the course of these informal discussions, which have been largely overlooked in previous historiography, the Soviets proposed several important projects for a post-war settlement in Europe. These proposals were largely agreed upon by Western representatives. A consensus was reached on the issue of changing the Soviet-Polish and Polish-German borders, which was subsequently updated and ratified at the Yalta and Potsdam conferences. Additionally, the article addresses other matters pertaining to the Tehran Conference, including discussions on German war criminals, the role of interpreters, and other pertinent topics.