Battle for Castle Itter The Battle for Castle Itter was fought in the final days of World War II in Europe , five days after the death of Adolf Hitler . The 23rd Tank Battalion of the US 12th Armored Division led by Lieutenant John C . " Jack " Lee , Jr . , anti - Nazi German " Wehrmacht Heer " soldiers , and imprisoned French VIPs defended the castle against the 17th " Waffen - SS Panzer Grenadier " Division . The French prisoners included former prime ministers , generals , and a tennis star . Popular accounts of the battle have called it the " strangest " battle of World War II . It was the only battle in the war in which Americans and Germans fought as allies . Background . Itter Castle , " Schloss Itter " , is a small castle situated on a hill near the village of Itter in Austria . After 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 February 7 , 1943 . The transformation of the castle into a prison camp was completed by April 25 , 1943 , and the facility was placed under the administration of the Dachau concentration camp . The prison was built to contain high - profile prisoners valuable to the " Reich " . Notable prisoners included tennis star Jean Borotra , former prime minister Édouard Daladier , Charles de Gaulle ' s elder sister Marie - Agnès Cailliau , former commander - in - chief Maxime Weygand , former prime minister Paul Reynaud , former commander - in - chief Maurice Gamelin , right - wing leader 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 . Battle . The commander of the prison , Sebastian Wimmer , fled on May 4 after the suicide of Eduard Weiter , the last commander of Dachau . The " SS - Totenkopfverbände " guards departed the castle soon after . The prisoners took control of the castle and armed themselves with the weaponry that remained . Zvonimir Čučković , a Yougoslav resistance member imprisoned in Itter , left the facility in search of Allied assistance two days prior to Wimmer ' s departure . Čučković encountered the American 103rd Infantry Division near Innsbruck and informed them of the castle ' s prisoners . Major Josef Gangl , commanding a unit of " Wehrmacht " soldiers , and who had collaborated with Austrian resistance in the closing the days of the war , had intended to free the castle prisoners , but decided instead to surrender to the Americans . A rescue of the Itter VIPs was planned . Lieutenant Lee volunteered to lead the rescue mission , and was accompanied by Gangl ' s soldiers . Lee ' s forces now consisted of fourteen American soldiers , two Sherman tank s , a Volkswagen Kübelwagen and a truck carrying ten German soldiers . " En route " , the small column defeated a party of SS troops that had been attempting to set up a roadblock , then left one of their Shermans behind to guard a bridge . The French prisoners greeted the rescuing force when it arrived at the castle , but were disappointed at its small size . Lee placed the men under his command in defensive positions around the castle , and placed his Sherman tank , named " " Besotten Jenny " " , at the main entrance . The " Waffen - SS " began their attack on the castle soon afterwards , on the morning of May 5 . The Sherman tank provided machine - gun fire support until it was destroyed by German fire . Lee had ordered the French prisoners to hide , but they remained outside , and fought alongside the American and " Wehrmacht " soldiers . A relief force , the American 142nd Infantry Regiment , arrived and the SS were defeated . Historical significance . For his service defending the castle , Lee received the Distinguished Service Cross and was promoted to Captain . Gangl died during the battle from a sniper ' s bullet , but was honored as an Austrian national hero and had a street in Wörgl is named after him . Popular accounts of the battle have dubbed it the " strangest " battle of World War II . The battle was fought five days after Adolf Hitler had committed suicide . It was also the only battle where Americans and Germans fought as allies during the war , and the only battle in American history fought in a medieval European castle .