After the German and Soviet attack on Poland in 1939, vast swathes of Polish territory, including Warsaw and Kraków, fell under Nazi occupation in an administration which became known as the 'General Government'. The region was not directly incorporated into the Reich but was ruled by a German regime, headed by the brutal and corrupt Governor General Hans Frank. This was indeed the dark heart of Hitler's empire. As the principal 'racial laboratory' of the Third Reich, it was the site of Aktion Reinhard, the largest killing operation of the Holocaust, and of a campaign of terror and ethnic cleansing against Poles which was intended to be a template for the rest of eastern Europe. This book provides a thorough history of the General Government and the experiences of the Poles, Jews and others trapped in its clutches. Employing previously underused sources, Martin Winstone provides a unique insight into the occupation regime which dominated much of Poland during World War II.