A National Trust volunteer has written a book about the role of northern rocks in the Roman occupation.

Ian Jackson, who has been a guide at Hadrian’s Wall and Housesteads Fort for more than 10 years, has used his geological expertise and knowledge of Roman history to pen "The Rocks at the Edge of the Empire."

Mr Jackson said: "Over the years of taking people around the fort, I steadily realised just how many things in the fort had been provided by our northern rocks.

"Sandstone and limestone for building, metals for swords, slingshots and tools.

"The Romans used local coal to smelt the metals and for their heating and bath houses.

"They ground their flour and sharpened their knives on sandstone, cooked in copper and clay pots.

"Lead made their pipes and coffins and even make-up, ochre and umber made their pigments and paint."

This realisation prompted Mr Jackson to delve deeper into the subject.

By overlaying geological maps on top of plans of Roman defences, he discovered the extent to which the rocks had influenced their design and routes.

The book is available from local booksellers and at The Sill: National Landscape Discovery CentreThe book is available from local booksellers and at The Sill: National Landscape Discovery Centre (Image: Ian Jackson)

He found that the Whin Sill ridge defined the route of Hadrian’s Wall across the Solway-Tyne isthmus, and the need to avoid the hard Whin and soft peat deposits is the reason the Vallum keeps changing course.

Kay Owen, visitor operations and experience manager at the National Trust, said: "We are delighted with the book.

"Our voluntary guides do a fantastic job, each of them brings their individual approach and talents to taking thousands of visitors around Housesteads, Hadrian Wall’s premier site.

"The insights and knowledge contained in the beautifully illustrated and accessible book that Ian has produced will enrich these tours even more and bring additional visitors to the Fort."

Ian began to appreciate just how much the rocks had influenced Roman design and routesIan began to appreciate just how much the rocks had influenced Roman design and routes (Image: Ian Jackson)

The book, which costs £12, is available from local booksellers and at The Sill: National Landscape Discovery Centre.

There will be book launch events throughout autumn including one at The Sill on November 10 where Mr Jackson will be talking about places in the book and signing copies.

For more information visit: www.northumberlandnationalpark.org.uk/whats-on/the-rocks-at-the-edge-of-the-empire-book-launch/