In the early pages of In the Land of Giants, Max Adams quotes an eighth-century Anglo-Saxon poem that describes the shattered stone shells and jagged masonry still standing, three centuries after the end of the Roman occupation of Britain. ‘A hundred generations/have passed away since then. This wall, grey with lichen/and red of hue, outlives kingdom after kingdom,’ the anonymous poet marvels. Adams’s latest book is very much an attempt to instil in the reader that same sense of wonder, cataloguing the huge range of monuments that survive in Britain from the little-documented period between the departure of the Roman legions early in the fifth century and Alfred the Great’s drubbing of the Danish Viking invaders over 450 years later.

Adams wisely warns readers that ‘narrative histories do not get us very far towards an understanding of these islands in the centuries after Roman rule’. Far from being a defeatist manifesto, this thought serves as a starting point for something entirely different. Adams embarks on a series of extended walks,