The Canon: The History of Britain. By John Milton

Not only do we not know what the future holds; often we have little idea what the past holds. For Francis Bacon: "Time is like a river, which has brought down to us things light and puffed up, while those which are weighty and solid have sunk." One weighty object is John Milton's magisterial The History of Britain (1670). The most substantial prose work published in his lifetime, it remains, in the words of John Morrill, "an abandoned and unloved gift". I prefer to see it as a Trojan Horse bequeathed to the imperial monarchy Milton spent his life attacking.

Modern critics express dissatisfaction with Milton's failure to get beyond the Norman Conquest and his pessimistic perspective on the Saxons, seen by others as a saving grace between the Romans and Normans. But Milton saw no Anglo-Saxon Golden Age betrayed, representing them as just another unworthy crew; likewise, the ancient Britons were "Progenitors not to be glori'd in". His anti-clericalism and republicanism mean short shrift for monks or monarchs. He drags down the icons of British mythology, none more so than Boadicea. Emasculating women are enemies of native manliness, and anxiety about female rule punctuates Milton's militantly masculine account: the elect nation is gendered.

Milton's History is deconstructive and postcolonial before its time, unpicking the stitches of ecclesiastical and monarchical authority, charting the experience of conquest, occupation and neocolonial corruption, constellating the contradictions of a country caught between colony and empire. For Milton, knowledge was power; self-knowledge the key to national liberty. Milton's is a hard lesson, a history conveying the same tough love as Yeats' September 1913.

Contemporaries saw Milton's History as a curtailed enterprise, "the Tale of a Man in a fright", but the most hair-raising aspect is its storehouse of home truths. Holding up a mirror to a nation reluctant to see itself close-up, History informs the later poetry. The prose tract exposing the workings of the nation-state is the groundwork for the epic verse. Britain is a failed state, a fallen state in need of regime change after honest insight into its ugly past. The History of Britain reads like a prose version of Paradise Lost, recounting a series of falls - invasions and occupations - holding out the promise of redemption.

Yet if his own nation's history turned out to be a mere chronicle of "the Warrs of Kites, or Crows, flocking and fighting in the Air", there was still hope. Milton's final plea is for a humanist solution: foreign books will civilise his country out of its slavish addiction to tyranny. Derided in its day, fated to obscurity in the ensuing three centuries, The History of Britain is a text for our time. Chaotic, quixotic, cathartic, it transformed my understanding of theories of nation. Sunken treasure buried beneath the mediocrity of a culture more versed in Andrew Marr than Andrew Marvell, it remains a rich resource informed by anti-colonialism, humanism and republicanism - marred by misogyny, but lit up by an electrifying lyrical power unsurpassed in Milton's poetry.