Dr Duncan B Campbell is a specialist in ancient Greek and Roman warfare. He published his first paper in 1984, as an undergraduate at Glasgow University, and produced a complete re-assessment of Roman siegecraft for his Ph.D. Over the years, his work has appeared in several international journals. He lives near the Antonine Wall in Scotland with his wife and son. Brian Delf began his career working in a London art studio producing artwork for advertising and commercial publications. Since 1972, he has worked as a freelance illustrator on a variety of subjects including natural history, architecture and technical cutaways. Some of his recently illustrated books have been published in over thirty countries. Brian lives and works in Oxfordshire.