Mairi Mackinnon has lived in England, Scotland, France, Italy and Spain, and worked as a teacher, translator and tour manager before joining Usborne. Over the years she has written and edited Usborne books in sixteen languages, from Arabic to Welsh. She lives in a house full of teenagers, books and curious musical instruments.

"As a boy, Arthur knows nothing about his real family. One day his foster father and brother attend a tournament, and his brother sends Arthur to fetch his sword. Arthur sees a sword in a stone. He doesn't know that only the true King of Britain can release it. With fun activities after the story, and online audio in British and American English."