Julia Donaldson has sold more than 50 million books in the UK, and in 2025 she was named the country's bestselling author across all genres since records began. The figure rests substantially on two picture books: The Gruffalo, published in 1999, and its 2004 sequel, The Gruffalo's Child, which together have sold more than 18.2 million copies worldwide.

The milestone carries a particular irony. In 1999, a journalist asked the then-unknown Donaldson, 51 years old and the author of just one previous book, to share her millennium wish. She said she hoped her new book, out that year, would become a classic. Then she immediately retracted it.

"But then straight away I said: 'Only joking!' Because I didn't want to sound full of myself, and I certainly didn't think the wish would come true," Donaldson recalls today.

The wish came true. The Gruffalo — the tale of the terrible creature with terrible claws and terrible teeth in his terrible jaws — became a fixture of British childhood, and Donaldson became the most commercially successful author in the country's recorded publishing history, outranking writers of both children's and adult fiction.

Donaldson is now introducing the latest member of her Gruffalo family, an occasion that prompted her to speak about storytelling, loss and the anxieties that accompany her status as Britain's all-time bestselling author.

Asked whether she identifies with the Gruffalo now that she is a grandmother figure to generations of readers, Donaldson rejects the framing outright.

"Am I the Gruffalo Granny? Not really. I'm the mouse," she says.

The distinction is telling. In her own story, the mouse is the small, quick-witted protagonist who survives through invention and nerve — not the looming monster the other animals fear. Donaldson, who began her publishing career late by industry standards and published only one book before the age of 51, casts herself as the underdog rather than the institution she has since become.

The numbers explain why the question arises at all. More than 18.2 million copies of The Gruffalo and The Gruffalo's Child have sold worldwide since their publication, a figure that spans translations, editions and more than two decades of continuous reprinting. The two books anchored a body of work that has now passed 50 million copies in the UK alone, the market on which the 2025 bestselling-author designation was based.

That designation, made since records began, places Donaldson ahead of every other author in British publishing history regardless of genre — a position she could not have anticipated when she made her self-deprecating millennium wish in 1999.

Her reflections now turn on the complications of that success. In interviews marking the new Gruffalo family member, she discusses storytelling and loss, and the worries that come with being Britain's all-time bestselling author — the pressures of a reputation built, in large part, on a single character she invented in middle age and nearly disowned as an ambition.

The new addition to the Gruffalo family suggests the franchise will extend further into a third decade, even as Donaldson, at 78, insists she still sees herself as the mouse in the deep dark wood rather than its most famous resident.