During the waning months of World War II, as the Soviet Red Army advanced into Silesia and encircled Fortress Breslau ("Festung Breslau"), Hanke was named by Hitler to be the city's "Battle Commander" ("Kampfkommandant"). Hanke oversaw, with fanaticism, the defense of the city during the Siege of Breslau. Goebbels, dictating for his diary, repeatedly expressed his admiration of Hanke during the spring of 1945. During the 82-day siege, Soviet forces inflicted approximately 30,000 civilian and military casualties and took more than 40,000 prisoners, while suffering 60,000 total casualties. On 6 May, the day before Germany's surrender, General Hermann Niehoff surrendered the besieged Breslau, the Soviet army already having reached Berlin. Hanke had flown out the previous day in a small Fieseler Storch plane kept in reserve for him.