Anthony Horowitz was born in 1956 in Stanmore, Middlesex, into a rich family. Raised in "a Jewish enclave", Horowitz lived an upper-class lifestyle. His father acted as a "fixer" for prime minister Harold Wilson. Facing bankruptcy, Horowitz's father removed his wealth from his bank accounts and hid it away under a pseudonym. He then died and the family was never able to track down the missing money despite years of trying. As an overweight and unhappy child, Horowitz enjoyed reading books from his father's library. At the age of eight, Horowitz was sent to the boarding school Orley Farm in Harrow, London. There, he entertained his peers by telling them the stories he had read. Horowitz described his time in the school as "a brutal experience", recalling that he was often whipped by the headmaster. Horowitz adored his mother, who introduced him to Frankenstein and Dracula. She also gave him a human skull for his 13th birthday. Horowtiz said in an interview that it keeps reminding him to keep getting to the end of each story since he will soon look like the skull. From the age of eight, Horowitz knew he wanted to be a writer, realising "the only time when I'm totally happy is when I'm writing".

In at least one interview, Horowitz claims to believe that H. P. Lovecraft based his fictional Necronomicon on a real text, and to have read some of that text.

Horowitz now lives in North London with his wife Jill Green, whom he married in Hong Kong on 15 April 1988. Green produces Foyle's War, the series Horowitz writes for ITV. They have two sons, Nicholas Mark Horowitz (born 1989) and Cassian James Horowitz (born 1991). He credits his family with much of his success in writing, as he says they help him with ideas and research. Horowitz is a patron of child protection charity Kidscape.

1979—1993

Anthony Horowitz's first book, The Sinister Secret of Frederick K Bower, was a humorous adventure for children, published in 1979 and later reissued as Enter Frederick K Bower. In 1981 his second novel, Misha, the Magician and the Mysterious Amulet was published and he moved to Paris to write his third book. In 1983 the first of the Pentagram series, The Devil's Door-bell was released. This story saw Martin Hopkins battling an ancient evil that threatened the whole world. Only three of four remaining stories in the series were ever written: The Night of the Scorpion (1984), The Silver Citadel (1986) and Day of the Dragon (1986).

In between writing these novels, Horowitz turned his attention to legendary characters, working with Richard Carpenter on the Robin of Sherwood television series, writing five episodes of the third season. He also novelized three of Carpenter's episodes as a children's book under the title Robin Sherwood: The Hooded Man (1986). In addition, he created Crossbow (1987), a half-hour action adventure series loosely based on William Tell.

In 1988, Groosham Grange was published. This book went on to win the 1989 Lancashire Children's Book of the Year Award. It was partially based on the years Horowitz spent at boarding school. Its central character is a thirteen-year-old "witch", David Eliot (based on the myth of the seventh child of a seventh child). Like Horowitz's, Eliot's childhood is unhappy. The Groosham Grange books are aimed at a slightly younger audience than Horowitz's previous books.

This era in Horowitz's career also saw Adventurer (1987) and Starting Out (1990) published. However, the most major release of Horowitz's early career was The Falcon's Malteser (1986). This book was the first in the successful Diamond Brothers series, and was filmed for television in 1989 as Just Ask For Diamond, with an all star cast that included, Bill Paterson, Jimmy Nail, Roy Kinnear, Susannah York, Michael Robbins, Patricia Hodge and starring Colin Dale and Dursley McLinden as Nick and Tim Diamond. It was followed in 1987 with Public Enemy Number Two, and by South by South East in 1991 followed by The French Confection, I Know What You Did Last Wednesday and The Blurred Man and most recently "The Greek who stole Christmas". Coming out soon is "The Radius of the Lost Shark". Horowitz also released a collection of rewritten Myths and Legends in 1991. He is still writing books to this day.

1994—2000

He wrote many stand-alone novels in the 1990s. 1994's Granny was Horowitz's first book in three years, and it was the first of three books for an audience similar to that of Groosham Grange. The second of these was The Switch, first published in 1996. The third was 1997's The Devil and His Boy, which is set in the Elizabethan era, and explores the rumour of Elizabeth I's secret son. In 1999, The Unholy Grail was published as a sequel to Groosham Grange.

The Unholy Grail was renamed as Return to Groosham Grange in 2003, possibly to help readers understand the connection between the books. Horowitz Horror (1999) and More Horowitz Horror (2000) saw Horowitz exploring a darker side of his writing. Each book contains several short horror stories. Many of these stories were repackaged in twos or threes as the Pocket Horowitz series.

2000—present

Horowitz began his most famous and successful series in the new millennium with the Alex Rider novels. These books are about a 14-year-old boy becoming a spy. He is a member of MI6. Currently, there are eight Alex Rider books: Stormbreaker (2000), Point Blanc (2001), Skeleton Key (2002), Eagle Strike (2003), Scorpia (2004) Ark Angel (2005) , Snakehead (2007) and Crocodile Tears (2009). The seventh Alex Rider novel, Snakehead, was released on 31 October 2007, and the eighth, Crocodile Tears, was released in the UK on 12 November 2009. There are plans for two further Alex Rider books, Yassen and Scorpia Rising.

In 2003 Horowitz also wrote three novels featuring the Diamond Brothers: The Blurred Man, The French Confection and I Know What You Did Last Wednesday, which were republished together as Three of Diamonds in 2004. The author information page in early editions of Scorpia and the introduction to Three of Diamonds claimed that Horowitz had travelled to Australia to research a new Diamond Brothers book, entitled Radius of the Lost Shark. However, this book has not been mentioned since, so it is doubtful it is still planned. A new Diamond Brothers "short" book entitled The Greek who Stole Christmas was later released. It is hinted at the end of The Greek who Stole Christmas that Radius of the Lost Shark may turn out to be the eighth book in the series. The Greek Who Stole Christmas by Anthony Horowitz — Red House Books

In 2004 Horowitz branched out to an adult audience with The Killing Joke, a comedy about a man who tries to track a joke to its source with disastrous consequences. Horowitz's second adult novel, The Magpie Murders, was due out on 18 October 2006. However, that date passed with no further news on the book; all that is known about it is that it will be about "a whodunit writer who is murdered while he's writing his latest whodunit" and "it has an ending which I hope will come as a very nasty surprise". As the initial release date was not met, it is not currently known if or when The Magpie Murders will be released.

In August 2005, Horowitz released a book called Raven's Gate which began another series entitled The Power of Five (The Gatekeepers in the United States). He describes it as "Alex Rider with witches and devils". The second book in the series, Evil Star, was released in April 2006. The third in the series is called Nightrise, and was released on 2 April 2007. The fourth book Necropolis was released in October 2008.

The Power of Five is a rewritten, modern version of the Pentagram series from the 1980s. Although Pentagram required five books for story development, Horowitz completed only four: The Devil's Door-bell (Raven's Gate), The Night of the Scorpion (Evil Star), The Silver Citadel (Nightrise) and Day of the Dragon (Necropolis). Horowitz was clearly aiming for the same audience that read the Alex Rider novels with these rewrites, and The Power of Five has gained more public recognition than his earlier works, earning number 1 in the top 10 book chart.

In October 2008, Anthony Horowitz's play Mindgame opened Off Broadway at the Soho Playhouse in New York City. Mindgame starred Keith Carradine, Lee Godart, and Kathleen McNenny. The production was the New York stage directorial debut for Ken Russell. Recently he got into a joke dispute with Darren Shan over the author using a character that had a similar name and a description that fitted his. Although Horowitz considered suing, he decided not to.

In March 2009 he was a guest on Private Passions, the biographical music discussion programme on BBC Radio 3.

Horowitz began writing for television in the 1980s, contributing to the children's anthology series Dramarama, and also writing for the popular fantasy series Robin of Sherwood. His association with murder mysteries began with the adaptation of several Hercule Poirot stories for ITV's popular Agatha Christie's Poirot series during the 1990s.

Often his work has a comic edge, such as with the comic murder anthology Murder Most Horrid (BBC Two, 1991) and the comedy-drama The Last Englishman (1995), starring Jim Broadbent. From 1997, he wrote the majority of the episodes in the early series of Midsomer Murders. In 2001, he created a drama anthology series of his own for the BBC, Murder in Mind, an occasional series which deals with a different set of characters and a different murder every one-hour episode.

He is also less-favourably known for the creation of two short-lived and sometimes derided science-fiction shows, Crime Traveller (1997) for BBC One and The Vanishing Man (pilot 1996, series 1998) for ITV. While Crime Traveller received favourable viewing figures it was not renewed for a second season, which Horowitz accounts to temporary personnel transitioning within the BBC. It has, however, attracted somewhat of a cult following. The successful 2002 launch of the detective series Foyle's War, set during the Second World War, helped to restore his reputation as one of Britain's foremost writers of popular drama.

He devised the 2009 ITV crime drama Collision and co-wrote the screenplay with Michael A. Walker.

Horowitz is the writer of a feature film screenplay, The Gathering, which was released in 2002 and starred Christina Ricci. He wrote the screenplay for Alex Rider's first major motion picture, Stormbreaker.

Groosham Grange

• Groosham Grange (1988)
• The Unholy Grail republished as Return to Groosham Grange (1999)

Alex Rider

• Stormbreaker (2000)
• Point Blanc (U.S. title: Point Blank) (2001)
• Skeleton Key (2002)
• Eagle Strike (2003)
• Secret Weapon (short story, 2003)
• Scorpia (2004)
• Ark Angel (2005)
• Snakehead (2007)
• Crocodile Tears (2009)
• Scorpia Rising (2011)
• "Yassen' (unknown)

The Diamond Brothers

• The Falcon's Malteser (1986/96)
• Public Enemy Number Two (1987)
• South By South East (1991/2001)
• The Blurred Man (2003)
• The French Confection (2003)
• I Know What You Did Last Wednesday (2003)
• The Greek Who Stole Christmas (2008)
• The Radius of the Lost Shark (2010)

Pentagram

• The Devil's Door-Bell (1983)
• The Night of the Scorpion (1983)
• The Silver Citadel (1986)
• Day of the Dragon (1989)

The Power of Five (The Gatekeepers)

• Raven's Gate (1 August 2005)
• Evil Star (2 April 2006)
• Nightrise (3 April 2007)
• Necropolis (30 October 2008)
• Title for Fifth Book is unknown.

Other novels

• Enter Frederick K Bower (1978)
• The Sinister Secret of Frederick K Bower (1979)
• Misha, the Magician and the Mysterious Amulet (1981)
• Robin of Sherwood: The Hooded Man (1986) (with Richard Carpenter)
• Adventurer (1987)
• New Adventures of William Tell (1987)
• Starting Out (1990)
• Granny (1994)
• The Switch (1996)
• The Devil And His Boy (1998)
• Half-Life (2001)

Adult novels

• William S. (1999)
• Mindgame (2001) (adapted later as a play)
• The Killing Joke (2004)
• The Magpie Murders (2006)

Collections

• Myths and Legends (1991)
• Horowitz Horror (1999)
• More Horowitz Horror (2001)
• The Kingfisher Book of Myths and Legends (2003)
• Three of Diamonds (2004)
• More Bloody Horowitz (2009)

Short stories

• "The Old Man of N3" (2009)