The initial books written by Dexter were
general studies textbooks. He began writing mysteries in 1972 during a family holiday.
Last Bus to Woodstock was published in 1975 and introduced the character of
Inspector Morse, the irascible detective whose penchants for
cryptic crosswords,
English literature,
real ale, and
Wagner operas reflected Dexter's own enthusiasms. Dexter's plots used
red herrings, "presenting Morse, and his readers, with fiendishly difficult puzzles to solve". He is assisted by James Hathaway, a detective sergeant played by
Laurence Fox. A prequel series,
Endeavour, features a young Morse and stars
Shaun Evans and
Roger Allam.
Endeavour was first broadcast on the ITV network in 2012, ending with the ninth series in 2023, taking young Morse's career into 1972. Dexter was a consultant for
Lewis and the first few years of
Endeavour. As with
Morse, Dexter occasionally made appearances in both series. Dexter set crosswords for
The Oxford Times as "Codex" (COlin DEXter). Some of these were published in 2006 as
Morse Crosswords (Chambers). He took the names for some of his characters, including Morse and Lewis, from other
cruciverbalists. All the characters in
Last Bus to Woodstock, the first Morse novel, were named after crossword compilers or entrants in
The Observers puzzles, "except the murderer". For example, although Dexter's military service was as a
Morse code operator, the character was named after his friend Sir
Jeremy Morse, a crossword devotee like Dexter. The music for the television series, written by
Barrington Pheloung, used a
motif based on the Morse code for Morse's name. ==Awards and honours==