Fiction:
* Historical Novels: He wrote several historical novels, including:
* "The Private Life of William Shakespeare" (1910) - A fictional account of Shakespeare's life
* "A Japanese Nightingale" (1913) - Set in 17th century Japan
* "The Tragedy of the Korosko" (1898) - A story set in Egypt
* "The Queen of the Congo" (1898) - An adventure story set in Africa
* Adventure Stories: Sladen wrote numerous adventure stories, often set in exotic locations.
* Detective Fiction: Sladen also ventured into detective fiction, writing stories featuring the detective "The Duchess of Bloomsbury."
* Short Stories: He published several collections of short stories.
Non-Fiction:
* Travel Writing: Sladen was a prolific travel writer, documenting his journeys around the world. His most famous work in this genre is:
* "Queer Things About Japan" (1893)
* Biography: Sladen wrote biographies of several notable figures, including:
* "The J. S. of S. A." (1915) - A biography of John Swinnerton Clipps, a prominent American newspaper editor
* "The Life of Admiral Lord Charles Beresford" (1915) - A biography of the British admiral
* Literary Criticism: Sladen also wrote essays and literary criticism.
Other:
* Plays: Sladen also wrote a few plays.
Sladen's work was often marked by his vivid descriptions, adventurous spirit, and interest in different cultures. He was a popular writer in his time, but his work has largely fallen out of favor. However, his historical novels, adventure stories, and travel writing continue to hold a certain appeal for readers interested in the history of literature and the early 20th century.