Doyle's literary inspiration often came from his natural interest in crime, and he had no tolerance for predators. Howell died in 1890 in circumstances as strange as any of Doyle's novels: His body was found near a Chelsea public house with his throat posthumously slit, with a half-Sovereign coin in his mouth. The presence of the coin was known to be a criticism of those guilty of slander.
The 1945 film The Woman in Green with Basil Rathbone and Nigel Bruce is a loose adaptation of this story. Milverton is replaced by Moriarty.
The story was faithfully adapted in the 1965 BBC series Sherlock Holmes with Douglas Wilmer as Holmes, and Barry Jones as Milverton. The only difference from the story is the identity of Milverton's killer.
The story was much extrapolated when adapted by Screenwriter Jeremy Paul for Granada Television series Sherlock Holmes starring Jeremy Brett. It became the 1992 feature-length episode The Master Blackmailer and featured Robert Hardy as the eponymous reptilian Milverton. Holmes's relationship with the maid is expanded upon, allowing Brett to suggest Holmes' buried tenderness and inability/unwillingness to indulge in matters of the heart. The violence of the villain's end, including the grisly grinding of the avenger's heel into the dead Milverton's bespectacled face, is faithfully adapted, but Holmes and Watson do not at the end gaze upon Milverton's killer's portrait, as the murderess is identified. Deviating from the original story, Holmes holds a very different opinion about the case's end. He requests Watson not to chronicle the case, deeming it to have unpleasant circumstances, whereas in the original story he's slightly more cheerful, as shown by his joking to Lestrade.
"Charles Augustus Milverton" was dramatised for BBC Radio 4 in 1993 by Bert Coules as part of his complete radio adaptation of the canon, starring Clive Merrison as Holmes and Michael Williams as Watson, and featuring Peter Vaughan as Milverton.
The third season of the BBC adaptation Sherlock features 'Charles Augustus Magnussen', portrayed by Lars Mikkelsen, as a primary antagonist. The episode "His Last Vow" aired 12 January 2014. In it, it is revealed that Charles Magnussen keeps the information with which he blackmails his victims in his own mind palace (inside his head), only occasionally acquiring hard copies when he has to. Despite Mycroft warning Sherlock to leave Magnussen alone as he is occasionally useful to the government, he is shot dead by Sherlock in order to free John from his power and guarantee Mary's safety, as Sherlock realizes by using his mind palace he has no actual evidence in the event of his death.
Holmes is hired by the débutante Lady Eva Blackwell to retrieve compromising letters from a blackmailer: Milverton, who causes Holmes more revulsion than any of the 50-odd Murderers in his career. Milverton is "the king of blackmailers". He demands £7,000 (over £800,000 in 2015) for the letters, which would cause a scandal that would end Lady Eva's marriage engagement. Holmes offers £2,000, all Lady Eva can pay, but Milverton insists on £7,000. It is worth £7,000 to him to make an Example of Lady Eva, ensuring his Future blackmail victims would be more "open to reason" and pay him what he wants knowing he will destroy them if they do not. Holmes resolves to recover the letters by whatever means necessary, as Milverton has placed himself outside the bounds of morality.
