Kate Cary was born outside Birmingham on 4 November 1967. She wrote her first book when she was four years old, and has been enthusiastic about writing ever since. Cary states that she has loved cats since the age of 6. She attended King Edward VI High School for Girls in Edgbaston, later moving to Surrey to study History at Royal Holloway, University of London (RHUL), where she graduated in 1989. After leaving the University, she began sending her books to publishers, regularly being rejected. Eventually, she discovered a small publisher who hired her to write “how to” and activity books. In 2003, Cary sent a writing sample to Victoria Holmes at Working Partners. Holmes offered her a position writing for the Warriors series, where she would share the workload with author Cherith Baldry and Holmes herself in order to keep up with the publishing schedule.

Cary moved to Scotland in 1992, where she gave birth to her son, Joshua, in 1997. Cary returned to England in 2004, where she now resides.

The first Bloodline book was written in 2005, simply entitled Bloodline. It is an unofficial sequel to Dracula and is an epistolary novel taking place during World War I. Kirkus Reviews praised its plot twists, but said that the novel had flat characterization. She also wrote a sequel titled Bloodline: Reckoning in 2007. Kirkus Reviews say that bad pacing and characterization hurt the story, but the tension is kept high by bluffs and mysteries.