Jan Gerhard Toonder is born in Rotterdam on the 18th of July, 1914. The writer Willem Kloos reads a novel in the making and commends Jan Gerhard for his work by written letter. This commendation convinces Jan Gerhard Toonder to cease with his economics course in order to pursue a career as a writer.

After initially writing some children's books using a pseudonym, he writes 'Een man zet door' (A man perseveres) at the request of his publisher who wanted 'a book suited for young adults'. It is the first book in a series of books, each with its own various style and content.

His books are a reflection of Jan Gerhard's many interests and moods. He finds that his own integrity as a writer should not be compromised by the grace of his audience. In 1957 he writes the surrealistic novel ‘Heksenest’ (Witches nest) containing pen illustrations made by his brother Marten Toonder. This book differs so entirely from his previous works that as result some of his readers become estranged.

In 1970 he established himself as a known writer by writing the national literature 7 day gift 'Kasteel in Ierland' (Castle in Ireland). Two of his novels, 'De spin in de badkuip' '(The spider in the bathtub) and 'De dronken kanarie' (The drunken canary) are effortlessly written autobiographic impressions. Together with John A. West, he composes an astrological argument which strongly reflects his conviction that astrology should be seen as a science. Jan Gerhard Toonder dies in Amsterdam on the 25th of August, 1992, after a productive life as a literary writer.