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Christopher Lloyd graduated with a double-first class degree in history from Cambridge University. Christopher became Technology Editor with The Sunday Times newspaper in London and is now a bestselling author of more than fifteen books on world history including What on Earth Happened? (Bloomsbury), the series of What on Earth Timeline Wallbooks, Absolutely Everything! and more. He is in great demand as a lecturer and public speaker throughout the world, including at TEDx talks, conferences, educational seminars, museums, festivals and schools.

J. E. Luebering is Executive Editor of Encyclopaedia Britannica. He lives in Chicago, Illinois.