Baker Street Wiki
Baker Street Wiki

Baron Manfred Gottfried Karl Wolfgang von Leinsdorf was a German nobleman who serves as the main antagonist of Nicholas Meyer's 1974 Sherlock Holmes novel, The Seven-Per-Cent Solution. A dissolute but devoted German nationalist, he is at the center of a conspiracy Holmes must race to unwind before it causes a general European war.


Leinsdorf was the son of Baron Karl von Leinsdorf and his first wife, a lesser Habsburg princess. The family originated in Bavaria, with relations to both the Bavarian and Austrian royal families. The younger Leinsdorf attended university at Heidelberg, but he left after three years under unfavorable circumstances. He had extremely conservative political views and was devoted to making Germany a great power, and was active in right-wing military circles. He also developed a reputation as a profligate playboy. He exhibited and unscrupulous behavior, particularly towards women, and racked up enormous gambling debts.

In 1891, the old baron died, leaving his vast fortune to his second wife, the former Miss Nancy Osborn Slater, whom he had married just two months before. The bulk of the baron's holdings were in the armaments industry, and he in fact controlled one of the largest munitions enterprises in Germany. It appeared that the baron may have married Miss Slater, a pacifistic Quaker, for the express purpose that she dismantle his arms holdings. The young baron could not allow this - not only did he need the fortune to cover his debts, his father's factories were critical to Germany's readiness for war. Some speculated that he may have used his connections to right-wing elements in the German government to bring about his father's death; either way, he immediately contrived to kidnap his stepmother, with the intent of forcing her to renounce the inheritance, and imprisoned her in Vienna.

The baroness managed to escape, but was picked up by the authorities after apparently attempting to commit suicide. At this time, Sherlock Holmes was in Vienna, being treated by Dr Sigmund Freud for a cocaine addiction. The baroness, who had become catatonic, was placed Freud's care, who asked for Holmes' help in unravelling the mystery of what had happened to her. Coincidentally, Freud had also just had a run-in with the young baron at a local club; Leinsdorf insulted Freud's Jewish heritage, resulting in a tennis match which the baron lost. Leinsdorf, meanwhile, had engaged a former lover, the actress Diana Marlowe, to act as his step-mother in public to prevent anyone from noticing her absence.

Holmes, of course, soon confirms that Freud's patient is the real baroness and the other woman is a fraud. He also realizes the extent of the baron's influence when he recognizes Alfred von Schlieffen, the head of the German military, outside the baron's mansion. Holmes soon understands that the consequences of the baron's maneuverings could set up a general European war, threatening millions of lives.

Word soon arrives that the baroness has been kidnapped again. Holmes realizes that Leinsdorf is taking his stepmother back to Germany, and that they must catch him before he crosses the frontier. After a breakneck chase, they catch up to the baron's train. A fight ensues between Holmes and Leinsdorf, which ends in the baron's death. They find the real baroness locked in a trunk, but alive.

Embarrassed, the German and Austrian governments cover up the affair and swear all the participants to silence; Watson reluctantly agrees out of consideration for Dr Freud. The plot, which involved the German chancellery and the Archduke Franz Ferdinand, heir to the Austrian throne, is seemingly defused. However, Holmes remarks that they have succeeded only in postponing a conflict, not preventing one, and he predicts the German government will use Leinsdorf's death and the baroness' mental state to assume control of the family's munitions empire.


  • Jeremy Kemp portrays Manfred von Leinsdorf in the 1976 film adaptation of the novel.