Following an apprenticeship in his father's printing and publishing shop, he took part as a one-year volunteer with the Royal Bavarian Life Guards in the First World War from 1914 to 1918.

He attained the rank of Leutnant of reserves and was awarded the Iron Cross, 2nd class, the Military Merit Order with swords, and the Wound Badge.

[1] Under Liebel's leadership, Nuremberg implemented the Nazi racial policies by purging the city administration of non-Aryans and others considered "undesirable".

In promising to carry out an even more extensive purge of teachers, Liebel was quoted as saying that the action "called for a good deal of brutality, and there is no lack of it.

The aim was to restore the city center to the medieval look of centuries past by exposing half-timbering and, in particular, eliminating late nineteenth-century styling.

He felt that this "foreign" building with its Moorish revival architecture could not be reconciled with the "Old German" image that he strove to create.

Beginning in November 1941, the police president of Nuremberg, then-SS-Brigadeführer Benno Martin, oversaw the deportation of over 1,300 Jews.

It was Liebel who informed Speer, who had been absent from Berlin in September 1944, of Hitler's determination to implement a scorched earth strategy.

Although accounts of his death differ, most indicate that he died of suicide by a gunshot to the head in the early hours of 20 April – coincidentally on Hitler's 56th birthday.

This is the version recounted by Oberst Richard Wolf [de], a senior Wehrmacht commander present in the police bunker.