Hellsing wrote many children's books and specialised in a highly rythmicseemingly effortless and ingenious rhymes. In a book about Hellsing, biographer Nisse Larsson wrote: "Alongside Astrid Lindgren he, too, has been a portal figure in formulating Swedish children's literature as it is today."
Hellsing had a Scottish grandmother, who introduced him to many English nursery rhymes. Later, he translated many of these and published various collections of children's rhymes in Swedish. "His own poetry has certainly also taken inspiration from the English nonsense tradition," writes Nisse Larsson.
He also translated A A Milne's books about Winne-the-Pooh into Swedish, and more recently, the children's books of Julia Donaldson, such as the Gruffalo and Room on the Broom.
Hellsing's first book was published in 1943, and he continued writing and publishing books until very recently.
Lennart Hellsing passed away in the early hours of Wednesday morning. In a press statement, his family wrote: "until the very end, he was a uniting force in his big family and speak warmth and a feeling of safety around him. He will be sorely missed."