Sam McBratney, the author of the bestselling picture book Guess How Much I Love You, has died at the age of 77. The Northern Irish author died on 18 September, his publisher Walker Books announced on Monday. A former teacher, McBratney was the author of more than 50 books and scripts, but was best known for Guess How Much I Love You, the story of Little Nutbrown Hare and Big Nutbrown Hare and their efforts to express their love for each other. First published in 1994, illustrated with Anita Jeram’s watercolours, the children’s classic has sold more than 50m copies worldwide, and been translated into 57 languages. Sam McBratney, author of Guess How Much I Love You Sam McBratney, author of Guess How Much I Love You. Photograph: Simon Graham/Harrison Photography Walker said that McBratney’s phrase, “I love you to the moon and back” had “taken on iconic status”, while the book had sparked an animated TV show, a stage play and toys. But for McBratney, the book was just “a lighthearted little story designed to help a big one and a wee one enjoy the pleasure of being together”. “You turn the pages, you read the words, you do the actions and you play the game. This evening, somewhere in the world, a mum or dad will be reading Guess with someone special,” he said last year, to mark the book’s 25th anniversary. “I’d like to share with you one comment a father sent me. He wrote: ‘On good nights my little girl loves me all the way to the moon, but on bad nights she only loves me to the door.’ If you’re a parent (or a grandparent like myself), here’s hoping that you mostly make it to the moon. And back …” McBratney, who said that “it’s as difficult to write a fine picture book, one that stands out from the crowd, as it is to write a fine novel”, praised Jeram’s illustrations, saying that “there’s a gangly awkwardness, a boneyness, about hares, that [she] has captured, and with such a lovely soft palette”. Sign up for Bookmarks: discover new books in our weekly email Read more A sequel to Guess How Much I Love You, called Will You Be My Friend?, is due to be published on 29 September. “When writing about the hares, I aim to describe moments of emotional significance but with loads of humour and the lightest of touches. This story is about one of those moments. Little Nutbrown Hare’s world suddenly glows with the discovery of friendship,” McBratney said of that book. Born in Belfast, McBratney went to grammar school and then to Trinity College, Dublin, before working as a teacher at a further education college, a grammar school and a primary school. He took early retirement to focus on his career as an author, travelling the world to share his books with readers. “As Guess How Much I Love You achieved great success and acclaim, Sam never failed to express his profound surprise at the power of the message within his text. The joy he felt at knowing so many people around the globe connected with the gentle celebration of unconditional love was ever palpable,” said Donna Cassanova at Walker Books. “It is also the true mark of the man that he never failed to recognise the role that Anita Jeram’s exquisite illustrations play in the success of Guess How Much I Love You. They were a literary pairing of the highest calibre. Sam faced everything in life, and death, with such great, good grace and humour. He always smiled out at the world, and I feel so lucky to have felt the warmth of his smile.” McBratney is survived by his wife of 56 years, Maralyn, their three children, and six grandchildren.