In his most famous exploit, Voigt masqueraded as a military officer of the elite Prussian Guards in 1906, rounding up a number of Imperial German Army soldiers under his "command", "arresting" the Mayor of Köpenick, and "confiscating" 4,002 marks from the city treasury.

He was briefly employed by a well-reputed shoemaker until the local police expelled him from Berlin as an undesirable, based solely on his being an ex-convict, on 24 August 1906.

Then he took a train to Köpenick, east of Berlin, occupied the local city hall with his soldiers and told them to cover all exits.

He had the treasurer von Wiltberg and mayor Georg Langerhans arrested for political corruption, and confiscated 4002 marks and 37 pfennigs, issuing a receipt for the money signed with his former prison warden's name.

He told the remaining soldiers to stand in their places for half an hour and then left for the train station, where he changed back into civilian clothes and disappeared with the money.

There are claims that even the Kaiser was amused by the incident, referring to him as an amiable scoundrel, and being pleased with the authority and feelings of reverence that his military obviously commanded in the general population.

In its 27 October 1906 issue, the editors of The Illustrated London News noted gleefully: For years the Kaiser has been instilling into his people reverence for the omnipotence of militarism, of which the holiest symbol is the German uniform.

In spite of the ban he toured in Dresden, Vienna and Budapest in variety shows, restaurants and amusement parks.

Although his United States tour almost failed because the immigration authorities refused to grant him a visa, he arrived in 1910 via Canada.

Voigt's exploits became the subject of literary references as early as 1911, when British satirical writer Saki defined the term "to koepenick" as "to replace an authority by a spurious imitation that would carry just as much weight for the moment as the displaced original" in his short story "Ministers of Grace".

An English-language adaptation was written by John Mortimer, and first performed by the National Theatre company at the Old Vic on 9 March 1971 with Paul Scofield in the title role.

After the debacle, Luftwaffe chief Hermann Göring sent an ironic telegram to all concerned congratulating them on "the successful defence of the fortress of Koepenick".

The basic line of stageplays and movies was the pitiful catch-22 situation of Voigt trying to earn his living honourably in Berlin: "No residence address – no job.