Rome escape line trilogy

"September 1943: German forces occupy Rome. Gestapo boss Obersturmbannführer Paul Hauptmann rules with terror. Hunger is widespread. Rumors fester. The war's outcome is far from certain. Diplomats, refugees, and escaped Allied prisoners flee for protection into Vatican City, at one fifth of a square mile the world's smallest state, a neutral, independent country within Rome. A small band of unlikely friends led by a courageous Irish priest is drawn...