DEFENSIVE NORTHUMBERLAND, by Colin Alexander. Published by Amberley Publishing ( £14.99. Softback.

THOUSANDS of years before the Romans and the Venerable Bede, Northumberland was a landscape of Iron Age hilltop forts, many of which can still be traced today. Military order was imposed on the region by Hadrian’s legionaries who built the 73-mile northern frontier of the Roman Empire across the county.

Through the Dark Ages and into medieval times, the kingdom of Northumbria was governed from massive castles. Later, the constant threat of the border reivers led to the defensive necessity of fortified farmhouses, pele towers and churches. There are 600 recognised pele towers in England, of which 258 are in Northumberland. Examples featured include towers at Hepple, Alnham, Ponteland and Horsley and fortified churches at Edlingham and Ancroft.

The author also gives readers a comprehensive list of famous Northumberland battles. Thanks to the assistance of the Borders Gliding Club, the book features some exceptional aerial photographs taken by the author.