Spanish novelist Carlos Ruiz Zafon, whose book “The Shadow of the Wind” sold more than 15 million copies, has died of cancer aged 55 in Los Angeles, his publishing house said on Friday.

Zafon began his career in juvenile literature before publishing the work, which became the most read Spanish novel after Miguel de Cervantes’ classic “Don Quixote”, Editorial Planeta said.

The novel - the first of a four-part series, which was translated into over 40 languages worldwide - was in 2014 selected by British publisher Penguin Classics as one of 26 “classics of universal literature”.

Zafon’s editors paid homage to the author by quoting from one of its passages: “Every book, every volume you see, has a soul. The soul of the one who wrote it, and the soul of those who read it and lived and dreamed with it,” Editorial Planeta posted on Twitter.

Barcelona-born but living in Los Angeles, California, Zafon was one of the Spanish language’s most successful writers, with critics often comparing him to Charles Dickens for his dense, Gothic style, fast-paced intrigue and colorful characters.

Zafon’s enduring fascination with his native city was evident in his works, where the mysteries of a bygone Barcelona loom as significantly as any human character.

Spanish Prime Minister Pedro Sanchez tweeted: “One of the most read and admired Spanish authors worldwide has left us. Carlos Ruiz Zafon, a contemporary novelist of reference, leaves an important mark in modern literature. Thank you for letting us travel through your stories.”

A message on Zafon’s own Twitter account confirming his death said: “We’ll continue dreaming with every word he wrote.”