Sean Callery originally trained and worked as a journalist before he became a primary school teacher.

He writes both fiction and nonfiction and has written over sixty books for children. He has a particular passion for history and has a knack for mining little tantalising nuggets of information that you might have missed before.

Dr Mike Goldsmith studied the philosophy of time and space at Keele University, UK, where he also obtained his PhD in astrophysics. He was formerly the head of Acoustics at the UK's National Physical Laboratory and is now an author of non-fiction books for children, including the Kingfisher Space Encyclopaedia.