His father was a wealthy coal and timber merchant and so 'Willie' had a good education. Unfortunately, he suffered from very severe asthma which resulted in his being sent to Australia for 3 years to help him recuperate. While there he worked as a tutor. The background knowledge he acquired there, he put to good use later when he was trying to establish himself as a writer.

He was very keen on cricket, but his playing-skills were limited.

He married Constance Aimée Monica Doyle on 27th September 1893, and they had one son (Arthur Oscar who was killed in action in the first World War aged 21). This marriage made him the brother-in-law of Arthur Conan Doyle.

It is a lovely irony that these two were the creators of such well-known characters (Sherlock Holmes and Raffles) on opposite sides of the law. Hornung's first Raffles book was dedicated:

Though he wrote some other books, it is the Raffles stories for which he is chiefly remembered today. There were 26 in total which, at the time, were very popular 'best sellers'.

Whilst on holiday with his wife in France he caught a chill which turned into aggravated influenza and pneumonia and he died on 22nd March 1921 at St Jean de Luz, France, aged 54.

The entire Raffles collection consists of:
1899   The Amateur Cracksman
1901   The Black Mask
1905   A Thief in the Night
1909   Mr Justice Raffles
Raffles has been used many times as the central character in various plays, films and television episodes. The first film was 15 minutes long in (silent) black and white, and made in 1905.