'Lena' was a German intelligence programme to gather information about the UK, through the use of agents, as an aid to the planning of the 'Seelöwe' planned invasion (June/September 1940).

Within 'Lena', at least 20 agents were sent to England by boat or landed by parachute to gather information on the British coastal defences. The wholly inadequate nature of the German undertaking is reflected in the fact that many of these agents spoke only limited English. All of the agents were quickly captured and many were convinced to defect by MI.5’s 'Double-Cross' effort, otherwise known as the 'XX' system, which was overseen by the Twenty Committee. The turned Germans agents were then used to provide disinformation to their German superiors.

It has been suggested that the this very poor intelligence-gathering effort was the result of deliberate sabotage by the head of the Hamburg’s army intelligence bureau, Herbert Wichmann, in an effort to prevent a disastrous and costly invasion. Wichmann was critical of the Nazi regime and had close ties to Admiral Wilhelm Canaris, the former head of the Abwehr who was later executed by the Nazis for treason.

While some of the German intelligence errors might not have caused problems, others, such as the inclusion of bridges that no longer existed and misunderstanding of the utility of minor British roads, would have been a major impediment to the conduct of German operations, and would have added to the confusion caused by the layout of Britain’s cities and the removal of road signs.