Augusto Roggen was born in Montevideo in 1881, the son of a German who became a Uruguyan citizen four years later and, when he grew up, he married a German lady. Described as small, dark, neat and dapper, he did not look German, and he had developed a good command of English.
The mission which was to lead to his death began when he sailed from the Dutch port of Rotterdam on ss Batavia, arriving at Tilbury Docks on 30 May 1915. He was interviewed by the Aliens Officer, and said that he intended to travel to Scotland. This was allowed, and he arrived in Edinburgh on 5 June.
On his way he visited agricultural suppliers in London and Lincoln, claiming to be a farmer on business, but those he spoke to thought him patently ignorant of the subject, and he appeared to have no references. When registering at the Carlton Hotel in Edinburgh, he again indicated that he was a farmer and said he was interested in agricultural vehicles.
The following day he registered with the police and, rather oddly, told the officers that while in Germany he had been under suspicion as a spy and was kept under surveillance.
That same day he asked the hotel manager's wife about going around the Trossachs and the availability of local hotels. He went there on a day's outing, but on his return said that he preferred to travel to Tarbet where he intended to stay and fish. He had no fishing gear, but it was often possible to hire tackle, especially for sea fishing.
Before leaving the capital, he sent two postcards to H Flores, Binnenweg 127, Rotterdam. They were both intercepted, as they had been sent to an address familiar to the security services. They were copied, then allowed to carry on their postal journey, but the authorities now began to take a close interest in his activities.
Augusto was not aware of this when he booked into the Tarbet Hotel on 9 June. He bought a map of Loch Lomond and the head of Loch Long - a restricted area where fishing was banned. Nearby Succoth was also the home of the Royal Navy torpedo testing range.
The authorities were extremely worried about Augusto's presence on Loch Lomondside, so within five hours of his arrival at the picturesque hotel at the junction of the Arrochar and Crianlarich roads, there was a dramatic police swoop led by Superintendent John Wright of Helensburgh Police.
He was immediately arrested, and a search of his room revealed damning evidence - a loaded Browning revolver with 50 rounds of ammunition, invisible ink, and contacts details.
Perhaps not surprisingly, the Helensburgh and Gareloch Times did not report the incident at the time, presumably because of wartime censorship, but they did refer to it after the war, referring to Augusto as "a dangerous type".
Events moved swiftly after the arrest. Superintendent Wright escorted the prisoner to London, where he and his luggage were handed over to Inspector Edmund Buckley of Special Branch at Scotland Yard. He was unable or unwilling to explain the postcards sent to known enemy espionage addresses.
He was tried by a court martial at Middlesex Guildhall in Westminster on 20 August before the president, Major General Lord Cheysmore. He gave no evidence, made no statement, was found guilty, and was sentenced to death by shooting.
An appeal for clemency was received at the War Office from the Uruguyan Ambassador, and in the interests of diplomacy it was thought prudent to delay the execution and give the representation due consideration. However it was concluded that there was nothing in the note of appeal which would warrant a different course of action.
This remarkable tale of a spy whose relatively insignificant activities achieved absolutely nothing and for which he was to pay with his life was concluded at 6am on 17 September 1915 at the Tower of London.
Augusto Alfredo Roggen was shot by a firing squad composed of men from the 3rd Battalion, Scots Guards. Observers considered that he faced his death as a brave man, marching to the chair with a defiant air and bearing, and refusing to have his eyes blindfolded.
Reproduced with the kind permission of Helensburgh Heritage and the author, Donald Fullerton.