Itter Castle is a small castle situated on a hill near the village of Itter in Austria. Following the Anschluss, the German annexation of Austria, the German government officially leased the castle in late 1940 from its owner, Franz Grüner. The castle was seized from Grüner by SS Lieutenant General Oswald Pohl under the orders of Heinrich Himmler on 7 February 1943. The transformation of the castle into a prison camp was completed by 25 April 1943, and the facility was placed under the administration of the Dachau concentration camp.
The prison was established to contain high-profile prisoners valuable to the Reich. Notable prisoners included tennis player Jean Borotra, former prime ministers Édouard Daladier and Paul Reynaud, former commanders-in-chief Maxime Weygand, and Maurice Gamelin, Charles de Gaulle’s elder sister Marie-Agnès Cailliau, right-wing leader and closet French resistance member François de La Rocque, and trade union leader Léon Jouhaux. Besides the French VIP prisoners, the castle held a number of Eastern European prisoners detached from Dachau, who were used for maintenance and other menial work.
On 3 May, Zvonimir Čučković, an imprisoned Yugoslav communist resistance member who worked as a handyman at the prison, left the castle on the pretense of an errand for commander Sebastian Wimmer. He carried with him a letter in English seeking Allied assistance he was to give to the first American he encountered.
The town of Wörgl lay 8 kilometers (5 miles) down the mountains, but was still occupied by German troops. Čučković instead pressed on up the Inn River valley towards Innsbruck 64 km (40 mi) distant. Late that evening he reached the outskirts of the city and encountered an advance party of the 409th Infantry Regiment of the American 103rd Infantry Division of the US VI Corps and informed them of the castle’s prisoners. They were unable to authorize a rescue on their own but promised Čučković an answer from their headquarters unit by morning of 4 May.
At dawn a heavily armored rescue was mounted, but was stopped by heavy shelling just past Jenbach around halfway to Itter, then recalled by superiors for encroaching into the territory of the U.S. 36th Division to the east; only two jeeps of ancillary personnel continued.
Upon Čučković’s failure to return, and fearing for his life Eduard Weiter, the commander of the prison, abandoned his post. The SS-Totenkopfverbände guards departed the castle soon after, with the prisoners taking control of the castle and arming themselves with the weaponry that remained.
Failing to learn of Čučković’s effort, prison leaders accepted the offer of its Czech cook, Andreas Krobot, to bicycle to Wörgl mid-day on 4 May in hopes of reaching help there. Armed with a similar note he succeeded in contacting Austrian resistance in that town, which had recently been abandoned by Wehrmacht forces but reoccupied by roving SS. He was taken to Major Josef Gangl, commander of the remains of a unit of Wehrmacht soldiers who had defied an order to retreat and instead thrown in with the local resistance, being made its head.
Gangl had intended to free the castle prisoners, but was unwilling to sacrifice the few troops he had in a suicidal attack on a heavily defended fortress manned by the SS; instead, he was conserving them to protect local residents from SS reprisals, in which troops shot at any window displaying either a white or Austrian flag and summarily executed males as deserters, traitors, and defeatists. His hopes were pinned on the Americans reaching Wörgl promptly and surrendering to them. Instead, he would now have to approach them under a white flag to ask for their help.