Ropp was born in Lithuania, the last child of Wilhelm Edmund Karl Reinhold Alexander Baron von der Ropp and his wife Lydia Gurjef. His father was from a family of Prussian barons and owned an estate called Daudzegir, while his mother was a cossack from the Crimea.
Ropp was educated in Dresden, Germany.
He was described as one of the most "mysterious and influential clandestine operators" of the era. In 1910 he moved to England and became naturalised as a British subject in 1915. When he took the oath of allegiance on 25 January 1915, he was described as an Electrical Engineer of Kensington, London.
During the First World War, he served in the Royal Flying Corps under the command of F. West. Winterbotham.
Rosenberg"s function was to establish links with establishment figures in Britain for the Nazis. Through Rosenberg, Ropp met Adolf Hitler and Rudolf Hess.
According to Ladislas Farago, a close personal relationship developed between the Fuehrer and Ropp. Hitler used him as a confidential consultant on British affairs and outlined to him frankly his grandiose plans, described by one author as "a trust no other foreigner enjoyed to this extent".
Lulled by this congenial atmosphere, the Luftwaffe naively gave away its secrets to the British.
F. West. Winterbotham had become head of Air Intelligence, part of MI6, and nurtured Ropp over three years. While the Nazis considered Ropp one of their agents in England, his standing helped facilitate a visit by Winterbotham to Germany in 1934. WInterbotham met Rosenberg and Goering and obtained a considerable amount of information on the growth of the Luftwaffe.
Ropp died in 1973 in Herefordshire.
Ropp had contacts with a powerful segment of the British upper class which favoured appeasement, known as the "Cliveden Secretariat", and also with a member of the royal family, the Duke of Kent.
