'Gustav Siegfried Eins' was a British 'black' propaganda radio station during World War II operated by the Political Warfare Executive, and as such the precursor of 'Soldatensender Calais' (23 May 1941/late October 1943).

'Gustav Siegfried Eins' was created by Sefton Delmer, a former BBC German service announcer who had been recruited by the Political Warfare Executive during 1940, and claimed to be an illegal radio station operating within Germany. The station’s call sign was based on the German army phonetic alphabet for the letters GS, but had no meaning.

The programmes were recorded at the Wavendon Towers studio on glass discs which were then taken to the short-wave radio transmitters at Gawcott and Potsgrove.

The broadcaster was Peter Seckelmann, a refugee from Berlin, who used the name 'Der Chef' and claimed to be a patriotic Prussian officer of the old school, totally loyal to Germany. In the first 'Gustav Siegfried Eins' broadcast, on 23 May 1941 immediately after the flight to Scotland of Rudolf Hess, Adolf Hitler’s deputy, 'Der Chef' expounded that 'As soon as there is a crisis, Hess packs himself a white flag and flies off to throw himself and us on the mercy of that flat-footed bastard of a drunken old cigar-smoking Jew, Churchill!'

Most of the homilies by 'Der Chef' were aimed at low- and middle-ranking Nazi party officials, whom he portrayed as selfish, corrupt and sexually depraved gangsters whose behaviour shamefully contrasted with 'the devotion to duty shown by our brave troops freezing to death in Russia'.

The last broadcast, late in October 1943, ostensibly featured a Gestapo raid on the station in which 'Der Chef' was shot and killed. Unfortunately, the engineer who broadcast the transcription did not understand German, unfortunately, and broadcast the 'death' of 'Der Chef' twice.