Anglo-Saxon London suffers from an image problem, or more precisely from the problem that we have no image of it at all. In contrast to the showy glamour of Roman Britain, with its amphitheatres, temples and abundance of literature, or the vibrant cultural melting pot of the Tudor era, the Anglo-Saxon metropolis has almost no remaining visible architecture, a dearth of written sources and a patchy archaeological presence.

It is an arena from which historians have, perhaps wisely, shied away, but Rory Naismith’s Citadel of the Saxons manages to turn the slim pickings of the surviving evidence into something like a consistent narrative of the early days of London. It is a fascinating account of a period when it was more an overgrown village than a global city (or even a national capital).

Save in a few cases, such as Canterbury and St Albans, the Anglo-Saxons shunned the urban settlements of their Roman predecessors, which were reduced to stone husks that one of their poets described as ‘the works of giants’ in which ‘the roofs/Have fallen in, the towers have tumbled down’. How London survived at all, to be rebooted and become in the seventh century a modest trading settlement, is the first of the big issues that Naismith addresses in his account of what was the surprisingly complex development of the city in the early Middle Ages.

To do so necessitates a digression into the history of Roman London itself. This, while obviously fascinating, with its descriptions of Boudicca’s burning of London in AD 61 (the first of many conflagrations the fire-prone capital suffered) and of the Roman amphitheatre and writing tablets found in a dig beneath a new bank building, almost overshadows the book’s main subject.

Yet once Naismith does reach the Anglo-Saxon era, he rarely sets a foot wrong. The background is heavily drawn, as it must be to explain the ‘twisting kaleidoscope’ and ‘rapidly mutating landscape’ of the early Anglo-Saxon kingdoms, amid which London prospered by being a border territory not quite under the control of Mercia, Wessex or Kent, able to extract trading privileges from all of them while acting as a convenient neutral venue for diplomatic meetings, church synods and the signing of mercantile agreements.

Naismith ably sketches London’s progress from post-Roman ruinscape to Lundenwic, a small trading settlement centred near today’s Strand, and then to Lundenburh, a fortified town established inside the old Roman walls under Alfred the Great in the late ninth century, before finally describing its metamorphosis into London, the city that became an administrative, ecclesiastical and economic powerhouse in the century before the Norman Conquest.

There is a constant sense of London’s vulnerability. Throughout much of Naismith’s narrative, the city is overshadowed by others: Winchester was the favoured royal centre until well into the tenth century (no Anglo-Saxon king was buried in London between Saebbi of Essex in the late seventh century and Aethelred the Unready in 1016), while Norwich was for a long time far more vibrant economically, hosting a thriving ceramics industry. Yet almost because of its lack of royal patronage, London prospered, able to tap into Continental trade networks without the interference of covetous nobles while developing a sturdy self-reliance that enabled its inhabitants to see off a number of Viking attacks (in one of which, in 994, the raiders ‘suffered more harm and injury than they ever thought any citizens would do to them’). Its inhabitants established a ‘peace-gild’ in the tenth century (a type of vigilante outfit that policed the city and pursued criminals into neighbouring areas), and extracted guarantees from William the Conqueror in 1066 that the freedoms of the city and its citizens would be respected.

With his deft use of archaeology, the tenuous literary sources and numismatic evidence (as early as the first half of the seventh century, Anglo-Saxon coins were being inscribed with the name ‘Londuniu’), Naismith manages to weave together a very effective account of London’s political and economic development. Yet it is in the construction of a sense of the space of early London and its inhabitants that the book really comes to life. A mid-tenth-century charter describing the boundaries of the lands being granted as a ‘stream’, a ‘tree stump’ and the ‘Bulunga fen’ is a stark reminder that the ‘citadel of the Saxons’, for all its teeming alleyways and wattle-and-daub houses, was still a predominantly rural place. The warrior Imma, captured in a battle in 679 between Mercia and Northumbria and transported to London’s slave market to be sold (his bonds, miraculously, kept untying themselves, so his frustrated owners had eventually to free him), and King Cnut, who leapt, Archimedes-like, from his bathtub to dash, clad only in a cloak, to St Paul’s to explain his scheme to have an archbishop’s body moved from London to Canterbury, are just two of the characters who remind us that Anglo-Saxon London was a lively place and not just a repository of bones, quill pens and crumbling ruins.

At the very start of his work, Naismith quotes Bram Stoker’s Dracula, declaring his wish ‘to go through the crowded streets of your mighty London … to share its life, its change, its death, and all that makes it what it is’. It is a tall order to cover six of the most obscure centuries in London’s history and not leave readers dizzy and unsatisfied. In conjuring a fine sense of the topography of those Saxon streets, the lives of their inhabitants and the machinations of their rulers, Naismith has more than fulfilled his initial aspiration.