Medieval LEGO (September 2015, No Starch Press) teaches the fascinating history of medieval times through LEGO illustrations. It includes contributions from the world's leading scholars including Robert Bartlett, FA, FRSE of the University of St. Andrews, David D'Avray of University College London, and D'Arcy Jonathan Dacre Boulton, AIH FRHSC of the University of Notre Dame.
Greyson's desire to teach history in a way that young readers would find interesting and fun led him undertake the project at the age of 13. Since its publication, Medieval LEGO has taught and inspired thousands of young readers throughout the world. Medieval LEGO can be found in Barnes & Nobles, Books-A-Million, and on Amazon.com.