German troops crossed the Austrian border on March 12, 1938, without meeting resistance. Within hours, swastika flags hung from public buildings across Vienna as crowds gathered to cheer the union with Nazi Germany. For many Austrians, the Anschluss promised opportunity within the expanding Third Reich. For Jews and political opponents, it marked the beginning of exclusion and persecution.
Among those whose path suddenly opened was a young Austrian named Siegfried Seidl. Born on August 24, 1911, in Tulln an der Donau, Seidl grew up without a father, who went missing during the First World War. The collapse of the Austro-Hungarian Empire left the young republic politically unstable and economically strained, with deep divisions between left and right. Seidl was drawn early to radical nationalist ideas.
On October 15, 1930, at age 19, he joined the Nazi Party as member number 300,738. In September 1931, he entered the SA, the paramilitary formation known for intimidating political opponents. In May 1932, he transferred to the SS, the organization that would later control repression and the concentration camp system. His early membership suggests his commitment was ideological rather than opportunistic.
From 1935 until 1938, Seidl studied history and German studies at the University of Vienna. On March 2, 1939, he married Elisabeth Stieber, a former kindergarten teacher and devoted Nazi Party member active in the National Socialist Women’s League. The couple had three children. Their private life unfolded alongside Seidl’s growing role in a regime preparing for war and mass murder.
When the Second World War began on September 1, 1939, with the invasion of Poland, Seidl was called into police service due to his SS membership. In January 1940, he was attached to the Reich Security Main Office, known as the RSHA, the central authority coordinating the secret police, criminal police, and intelligence services. There, he worked under Adolf Eichmann, who organized the deportation of Jews from across Europe. Seidl was first sent to Poznań in occupied Poland, where he handled the resettlement of Poles and Jews from annexed territories.
In October 1941, Eichmann ordered him to establish the Theresienstadt Ghetto in the Protectorate of Bohemia and Moravia, about 37 miles north of Prague. The ghetto served as a transit camp for Jews from Germany, Austria, and the Protectorate who were to be deported to extermination camps in the east. It was also used for propaganda, presented as a model Jewish settlement to mislead the international community, including the International Red Cross. From November 1941 until July 1943, Seidl served as commandant of Theresienstadt.
Under his authority, approximately 121,000 people were deported to the ghetto. Around 25,000 died there, and nearly 44,000 were sent further east, where most were murdered. The ghetto was overcrowded from the start, with scarce food, insufficient medical care, and poor sanitation. Elderly inmates were especially vulnerable.
Seidl insisted on strict discipline and demanded to be addressed formally as “Mr. Camp Commandant. ” He banned heating and lighting in the barracks, measures with devastating consequences for the old and sick. People over 70 were assigned to cleaning duties, and those who disobeyed risked torture or inclusion in the next transport east.
Witnesses described Seidl as elegant and outwardly cultivated, interested in music and stamp collecting. He lived with his family in a three-bedroom apartment at a nearby hotel, owned a riding horse, enjoyed hunting, and had a sports car and a Mercedes company car. This contrast between private comfort and camp suffering reflected a broader pattern among SS leadership, where many combined bourgeois lifestyles with direct participation in persecution. Seidl was often present during the arrival of transports.
Survivors testified that he used a whip to force exhausted prisoners to move faster. On one occasion, he beat Oskar Löwy, a blind invalid war veteran, with a riding whip and punched him so hard that his prosthetic eye broke. Löwy’s only offense was asking about storing his luggage in a locker. In another incident, Seidl had a prisoner named Arthur Miller beaten so severely that he died days later.
Miller had arrived on the 13th transport from Vienna, and his offense was involvement in the sale of his parents’ mill. Under Eichmann’s orders, Seidl also organized the public hanging of 16 Jews accused of smuggling letters out of the camp, carrying out the order without hesitation. In autumn 1942, as thousands of elderly prisoners died, he reportedly commented that the clock was ticking correctly, a remark revealing his indifference to mass death. On July 3, 1943, Seidl was transferred to the Bergen-Belsen concentration camp in northern Germany.
There, he served as head of the camp Gestapo, responsible for Jews from neutral countries and regions such as Spain and South America. Allegedly, he interfered with personal documents and placed some individuals on deportation lists to Auschwitz. He later moved to the Mauthausen concentration camp in Austria to prepare for the deportation of Hungarian Jews. In March 1944, Seidl traveled to Budapest and joined the fifth Einsatzgruppe, a mobile SS killing formation.
He became part of Eichmann’s special deployment command, coordinating the deportation of Hungarian Jews. Between May 15 and July 9, 1944, in less than 60 days, approximately 440,000 Jews were deported from Hungary. Most were sent to Auschwitz-Birkenau, where around 80 percent were directed to the gas chambers upon arrival. Crematoria could not keep up with the number of bodies, and open pits were used to burn the dead.
Seidl participated in organizing confiscations and deportations in the city of Debrecen and later oversaw Hungarian Jews held in forced labor and concentration camps in Vienna and Lower Austria. The war in Europe ended on May 8, 1945. After the collapse of Nazi Germany, Seidl attempted to hide in Austria under a false name in Vienna. He was arrested in July 1945 and initially held by American forces before being transferred to Austrian custody.
Czechoslovakia requested his extradition for crimes committed in Theresienstadt, but Austrian authorities refused, arguing that many victims had been Austrian Jews. In October 1946, Seidl was brought before the Austrian People’s Court, a special tribunal established to prosecute Nazi crimes. He faced charges related to executions and abuses committed during his leadership of Theresienstadt. He was acquitted of specific murder charges but convicted of high treason and crimes against humanity.
During the trial, he first claimed he had only followed orders, a common defense among former SS officers. Later, he admitted his part in the atrocities. His doctorate, received in 1941, was formally revoked. Seidl was sentenced to death and ordered to forfeit all his property.
After hearing the verdict, he bowed calmly, but turned pale and began trembling. In the days that followed, he begged for mercy despite having shown none to his victims. His wife and mother petitioned the president for clemency, citing his three children. The petition was rejected.
On February 4, 1947, at 6:00 in the morning, the 35-year-old Seidl was hanged in Vienna. As the noose was placed around his neck, he told his executioner he was not sorry for the Jews he had killed and had nothing to regret. He was pronounced dead seven minutes later.
