Original Quadrilogy

The original Diary of a Neapolitan Mastiff quadrilogy consists of I, II: William Rules, III: A Jolly Christmas & ''IV: A Mastiff Hope. ''These four books were originally intended to be the only entries in the series, and follow the plot of the show it is based on. The original books follow loose story arcs and more generalised stories, as opposed to the more straightforward narratives of the sequels. All four were released in 2012. IV is still regarded as the final book in it several times.

The front cover and the inside of it are counted as pages 1 and 2 in the Original Quadrilogy books, the story thus beginning on page 3, unlike the Sequel Quadrilogy books which don't count the cover and starts the story on page 1.