This work constitutes an original piece of research and writing dedicated to relating the diplomatic initiatives (both official and unofficial, public and secret) that were intended to end or stop the spread of the Second World War in Europe. Special attention is given to specific peace proposals, initiatives, and back-channel diplomatic maneuverings, all within the general context of the foreign policies of the principal parties concerned. Diplomatic efforts designed to bring about an end to hostilities by belligerent and non-belligerent nations are included. Geographically, this work is confined to the European theater of operations. The chronological focus of this volume is on the earliest stages of the conflict, specifically from September 1, 1939, to September 1940. It is the intent of the author to expand the time period covered by way of future additions.