How long did cressida cowell write for?

Cressida Cowell, the British author and illustrator, began her writing career in the late 1990s. She is best known for her "How to Train Your Dragon" series, which started with the first book published in 2003. Since then, she has continued to write and publish numerous Children's Books, maintaining an active presence in the literary world. Overall, her writing career spans over two decades.