This book starts with the Incident at Mosty, in which we explore a little-known event which took place on August 25, 1939 near the Czechoslovakian/Polish border. The next chapter is The Gleiwitz Incident where we tell the story of an incident on the night of August 31/September 1, 1939, where the German Sicherheitsdienst (Security Service) staged a series of fake border incidents along the German-Polish frontier in Upper Silesia designed to give Nazi Germany an excuse for invading Poland. The most prominent of these provocations was the seizure of the German radio station in the town of Gleiwitz. Following from this we the describe the story of Westerplatte where the opening shots of the Second World War were fired in Poland: The Free City of Danzig, Westerplatte, The Military Transit Depot, Preparations for defense, Preparing for Aggression, The Last Hours of Peace, The First Day of War, The Second Day, The Third Day, The Fourth Day, The Fifth Day, The Sixth Day, The Seventh Day, Hitler Visits Danzig, Westerplatte Today. Finally, we describe The Siege of Warsaw in 1939. On September 8, 1939, one week into the Nazi invasion of Poland, German armored troops reached the gates of Warsaw. The Polish government and High Command had left the city but a determined garrison awaited the enemy invader and the Poles were able to stave off two consecutive German attempts to take the capital by armored attack. Thus began a siege that would last for three weeks and subject the Warsaw Army of over 100,000 and the civilian population of over one million to a ruthless campaign of aerial bombardment and heavy artillery shelling, causing thousands of casualties and widespread destruction. It was a hopeless battle that could only end in defeat and on September 27 the Polish garrison capitulated. The photos of the first penetration by tanks and infantry of the 4. Panzer-Division taken on September 9 became standard repertoire of German propaganda publications on the Blitzkrieg in Poland.