Janet and Allan Ahlberg met in the early 1960s. Janet studied graphic design, which led her to her vocation as an illustrator.

Several years later, bored with her then current job, and desperate for a creative opening, Janet asked Allan to write a children's book for her to illustrate. Allan, having always wanted to write but being unable to find his niche, suddenly felt 'as though [he] was a clockwork toy and she had turned the key'. So began the career which would later lead them to become one of Britain's most successful author/illustrator teams, producing ingenious books of the highest quality.

Influenced by comics and cartoons, their perfect partnership went on to produce masterpieces including Peepo!, which reflected Allan's childhood ('I am the Peepo! baby.'), Each Peach Pear Plum and The Baby's Catalogue. These books have all become children's classics, with their 'rhythmic prose, their mix of dottiness and sentiment appealing both to young children and to the parents who read them aloud' (Louette Harding, The Daily Mail). Working together, they saw their books as more than simply the combination of words and pictures - rather, a whole package which worked as a unity: 'the tale is not in the typescript or in the pictures but in a way the two go together, a marriage of words and pictures'. Striving for perfection, their main aim was 'to produce William Morris books at Penguin prices.'

1980 also saw the birth of their daughter, Jessica who was a great inspiration to their work. Janet passed away in 1994