He had trained at the Pinkerton Detective Agency in Chicago and spoke fluent English with an American accent.

During the visit Steinhauer foiled an assassination plot by a group of Russian anarchists on the Kaiser's life, working alongside British detective and spymaster William Melville.

In late July, the week before the declaration of the First World War, Steinhauer toured Britain under the alias 'Fritsches' to make contact with elements of his agent network, although MI5 knew he was present in the country they did not have the resources to mount sufficient surveillance to apprehend him.

[3] Vernon Kell, head of MI5, claimed to have ordered the arrest of 22 of Steinhauer's agent ring at the outset of war, leaving no significant German spies in Great Britain; but modern research has exploded this claim, which appears to have been made to promote the hasty passage of the Aliens Restriction Act of August 1914.

[4] Steinhauer later recalled the Kaiser's fury at the seeming obliteration of German surveillance of the British Navy screaming 'Am I surrounded by dolts?