Theresa Breslin is a Scottish author with a prolific career, having authored over 50 books. Her writing journey began in her teenage years, inspired by local industrial changes. Breslin pursued her passion, starting her publishing career while working as a librarian. Her dedication and talent were recognized in 1994 when she won the prestigious Carnegie Medal for her children's book, Whispers in the Graveyard. This novel specifically addressed themes relevant to young readers, featuring a protagonist with dyslexia. Her work has continued to garner attention, with other books like Prisoners of the Inquisition being shortlisted for major awards. Breslin's significant impact on literature was further acknowledged in 2019 when she was appointed an Officer of the Order of the British Empire (OBE) for her services to the field. She has also received an Outstanding Achievement Award from the Scottish Book Trust.

Hailing from Kirkintilloch, Scotland, Theresa Breslin began her writing career as a teenager, with early themes reflecting the impact of industrial decline. She developed her craft while employed as a librarian, a role that likely informed her extensive bibliography. Breslin has since published more than fifty books, establishing herself as a significant voice in children's and young adult literature. Her novel, Whispers in the Graveyard, published in 1994, earned her the esteemed Carnegie Medal, recognizing it as the year's outstanding children's book. This particular work focused on a young dyslexic character, showcasing Breslin's ability to connect with and represent diverse experiences. The quality of her writing has led to further accolades, including her book Prisoners of the Inquisition being a finalist for another Carnegie Medal in 2010.

Theresa Breslin's contributions to literature have been widely celebrated through numerous awards and honors. Beyond the significant Carnegie Medal, she has received an OBE in the Queen's Birthday Honours List for her dedicated services to literature. In 2000, the Scottish Library Association acknowledged her distinguished service to Children's Literature and Librarianship with an Honorary Membership. Her works have also been recognized by major American libraries, selected for the American Library Association's Best Books for Young Adults and the New York Public Library's Books for the Teen Age in 2003. Breslin was also awarded an Honorary Fellowship from the Association for Scottish Literary Studies in 2010 and received the Scottish Book Trust's Outstanding Achievement Award in 2019, the same year she was appointed OBE.

Among Theresa Breslin's notable works is Divided City, published in 2005, which marked her eighth book for the Doubleday list. Another significant publication is The Medici Seal, released in August 2006. This novel involved extensive research, including trips to study the iconic works of Leonardo da Vinci, such as the Mona Lisa and The Last Supper. The Medici Seal is described as a narrative filled with intrigue, murder, and betrayal, following the character Matteo on a journey across Italy alongside Leonardo da Vinci, engaged in the business of the Borgias. This demonstrates Breslin's capacity for historical research and weaving complex plots into her storytelling.