Charles Augustus Howell (10 March 1840 – 21 April 1890) was an art dealer and alleged blackmailer who is best known for persuading the poet Dante Gabriel Rossetti to dig up the poems he buried with his wife Elizabeth Siddal.

[4] Howell organised the exhumation of Dante Gabriel Rossetti's wife Elizabeth Siddal and the retrieval of the poems that he had left in her coffin in 1869.

[3] Swinburne blamed Howell, and after his death wrote that he hoped he was "in that particular circle of Malebolge where the coating of eternal excrement makes it impossible to see whether the damned dog's head is or is not tonsured".

[citation needed] The embarrassment of an inquest and police investigation was avoided when his death was ruled to have resulted from "pneumonic phthisis", the slit throat having been inflicted perimortem or posthumously.

[citation needed] The circumstances of Howell's death and the many rumours about his dishonesty and double dealings led to the accusation that he had used letters in his possession to blackmail prominent persons.

In the words of Humphrey Hare, "Fallen on hard days, Howell did not hesitate to blackmail by the threatened sale of letters which contained the customary puerile indecencies".

[10] However, his biographer, Helen Rossetti Angeli, could find nothing to support the accusations of blackmail, which possibly arose from extrapolations of the incident involving George Redway.

[11] In addition to the Sherlock Holmes story "Charles Augustus Milverton", Howell was the basis of the character De Castro in Theodore Watts-Dunton's novel Aylwin.