Sedley was born in Poole, Dorset and grew up in West London where visits to the local library instilled in him a life-long love of books. Sedley always loved writing and English. In fact, when he was eleven, he began a historical novel, now lost to posterity, but, if memory serves, in the style of Henry Treece and Ronald Welch. At school in Winchester he started to dream about a writing career, and was even lucky enough to win a prize for a short story, the title of which he has now forgotten. For some reason, however, the final line sticks in his mind. "Was it a living or waking dream? - No, she must be dead." After a brief flirtation with archaeology, he studied English at Nottingham University where he was tutored, for a term, by the Northern Irish poet, Tom Paulin. In the 1990s, he worked in fringe theatre and was involved in productions of Macbeth and Bertolt Brecht's In the Jungle of Cities. His own play, Salt Lake Psycho about the notorious murderer, Gary Gilmore was put on at the now defunct Man in the Moon theatre in Chelsea. Salt Lake Psycho was directed by Sean Holmes, current associate artistic director at Shakespeare's Globe. For the best part of two decades, Sedley lived and worked as a teacher and translator in Southern Italy. Here he collaborated with French writer, Claude Albanese on the screenplay of Dirty Waters. Dirty Waters, which is a political thriller, written with Italian blood, English sweat and French tears, received a commendation at the 2003 Montpellier Festival. In Italy Sedley continued to experiment with his writing, devising an invented dialect for a novel about a young female brigand of the Risorgimento. He also experimented with performance poetry, accompanying local blues band, Big Daddy Lawman on their tours of Apulian taverns, churches and bars. Returning to Britain in 2013, Sedley wrote The Half Days (2015), an ex-pat adventure set in Southern Italy. He struck up a writing partnership with Tony Henderson. Together they quickly published two books: Over & Under i (2015) and Over & Under ii (2016), a series of naughty tales, inspired by the tales of the Arabian Nights. The Over & Under Series has subsequently morphed into the Naughty Stories Series. The first in this series, Ten Naughty Stories was published in 2019 under the pen name, M. T. Sands. Sedley has also published the sequel to The Half Days under the title, Accidental Death of a Terrorist. Accidental Death of a Terrorist (2019) is the second part of the Mezzogiorno Trilogy. Sedley and Tony have written a children's book, The Wolf Garden, under the alias F. M. Frites: A Totally, Completely, and Utterly Bodacious Adventure with Unicorns and Gnomes.