Constitutional history once formed the backbone of British historical writing, to the point of furnishing the rationale for history itself. The mythic tale of the long march of British liberty, refined and tempered by the steady accumulation of experience, precedent, and moral principle, explained not only the remarkable stability and longevity of the country’s democratic institutions but also their unique capacity to deliver good government and orderly progress. The Civil War, the “Glorious” Revolution, the great reform acts of the nineteenth century, coupled with countless conventions, norms, and parliamentary procedures, were the mainstays of school and university curricula until at least the mid-twentieth century—before successive waves of historiographical innovation stripped them of their crown.

What unites the otherwise diverse cast of contributors to the Cambridge Constitutional History of the United Kingdom is the conviction that the pendulum has swung too far—that the diminished prominence of the subject over many years has now reached the point of studied neglect. While in no sense inviting a return to the “constitutional hagiography” of old (I, 8), the editors mount a spirited case for renewed attention to the legal, institutional, ideological, and mythical structures that have bound the United Kingdom through centuries of constitutional turbulence and political contingency. The twin contemporary challenges of a fractured Union and the fallout of Brexit animate the collection throughout, lending a fresh urgency to an age-old theme.

It is by any measure a serious undertaking—forty-two chapters spanning two volumes, the first devoted to thematic perspectives, institutional actors, and the ideological divisions that have shaped the long evolution of constitutional thinking; the second providing a chronological sweep of constitutional developments over time, and across the various sub-polities comprising the Union. This latter aspect surely counts as the collection's defining feature. What for more than a century had been framed in terms of the English Constitution (emblazoned on the spine of Bagehot's foundational work of 1867) is rendered here as the “Constitutional History of the United Kingdom”—incorporating extensive coverage of Scotland, Wales, and Ireland (alongside subregional and local perspectives) in ways that barely occurred to older generations of scholarship. In that sense, the two volumes are not simply restorative but avowedly innovative, redrawing the contours of the subject.

Though structured around three disciplinary pillars—the law, politics, and history—it is the latter where prior neglect has arguably been the most conspicuous, and hence the returns all the more rewarding. H. Kumarasingham’s anchor piece to Volume One doubles as a critique of the historical discipline’s early complicity in fostering a “reverential cult surrounding the constitution” (I, 9). But acknowledging this, he argues, should not distract us from the “deep ubiquity” of constitutionalism in British historical experience more generally (I, 33). He underlines the importance of a certain historical sensibility in anchoring a constitutional settlement otherwise unencumbered by formal codification.

This crucial dimension is taken up across several chapters in the first volume. Michael Gordon examines the legitimating force of history in cementing the UK constitution’s founding principle—what he calls the “historic character of parliamentary sovereignty,” relying on no other authority than the upshot of key historical episodes at decisive junctures (I, 319–20). Meanwhile, two outstanding back-to-back chapters by Asanga Welikala and Emily Jones deal respectively with Conservative and Liberal uses of a mythologized past to distinguish their core ideologies, each rooted in the instrumentalities of constitutional change. Equally, the binding force of received historical narratives has surely faded over time (the flipside of the constitution’s diminished standing in historical scholarship), allowing what Richard Bellamy terms a new “populist constitutionalism” to assert itself (I, 87).

Readers are thus presented with the paradox of a constitution revered for its stability, constancy, and capacity to evolve in reliably steady increments, yet sustained by a highly “elastic” constitutional historiography (I, 10). Peter Cane makes the crucial point that the nineteenth-century constitution underwent changes no less dramatic than what the eighteenth-century American colonists achieved virtually overnight. “By some sort of constitutional alchemy,” he observes, “the constitution of 1900 was essentially the same as, but also utterly different from, the constitution of 1800” (I, 43). History was a key register for absorbing the frequency and variety of new constitutional conventions necessitated by the upheavals of the Victorian era. For Robert Crowcroft, the nineteenth-century constitutional order was as much the product of endemic disorder actively promoted by the emergence of political parties. Since that time, he argues, an inherent malleability has remained the abiding “secret of the constitution,” with political parties frequently serving as “the instruments through which that was taken advantage of” (I, 452).

This points to another recurring theme in the chapters: the question of how long the system can hold. Many of the authors conclude on a note of hesitancy about the long-term durability of the constitutional status quo in the light of the political turbulence of recent years. Signs of increasing strain on parliamentary sovereignty, the vulnerability of the Monarchy, and the propriety of the church-state nexus are now widely debated amid calls for the system to be bolted down by a written constitution. The shadow of Brexit looms over much of this discussion, not least the constitutional impasse that attended Theresa May’s ill-fated EU Withdrawal Agreement in 2018–19.

Indeed, the constitutional implications of nearly half a century of EU membership resonated right across the board—from parliamentary procedure to conceptions of rights, citizenship, the judiciary, and the dispersal of power to the devolved legislatures. Vernon Bogdanor’s excursion into the novel procedures of direct democracy highlights how the Brexit vote marked the first nationwide referendum that brought about a change to the status quo, which the vast majority of the people's elected representatives opposed. “Europe,” he concludes, “has been responsible for the introduction of a new principle in the British constitution—the principle of the sovereignty of the people” (I, 250).

For the nineteenth-century constitutional historian William Stubbs, the “very diversity of the elements which are united within the isle of Britain” only underlined the “strength and vitality” of the constitution as a whole (II, 319). It would be fair to say that a very different perspective emerges from the chronological sweep of Volume Two. Here, the “diverse elements” are given far greater prominence, including constitutional prehistories of England, Ireland, Scotland, and Wales, arching back to the medieval period. But rather than trace a steady, harmonious pattern of constitutional convergence, the narrative detours, and digressions speak to the deeper fault lines of unionism. As Thomas Bartlett notes in the case of Ireland, taking a longer view only amplifies the “opposite paths of development” of the Irish and English parliaments from earliest times, which only complicated the uneasy merger of 1800 (II, 290). Andrew Blick concurs that the case of Ireland obliges us to “revisit the notion of continuity itself as a defining feature of UK constitutional history.” The serial ruptures that culminated in Irish Independence (and its long aftermath) bear witness to a constitution insufficiently “flexible and adaptable” to achieve a less traumatic outcome (II, 368).

Throughout the two volumes, the question of Scotland's future in the Union inevitably provides a recurring reference point. Though the strength of separatist sentiment has waxed and waned over the centuries, it was “given real impetus by the very device that was intended to contain it: devolution.” Stephen Tierney’s chapter on Scotland in the Union underlines how developments since the 2014 independence referendum have created a situation in which “Westminster’s unitary conception of the state has had to bend to accommodate the deeper sovereignty of a multinational and demotically plural United Kingdom” (II, 441–2). But at what point does dynamic constitutional “bending” reach breaking point?

Two fascinating chapters at the conclusion of Volume One take (implicitly) divergent views, with James Mitchell and Alan Convery more inclined to see unionism as a genuine and ongoing source of “loyalty and sense of belonging within each component to the wider state”—though for how much longer they resist being drawn (I, 520). Michael Keating, by contrast, sees only challenges, anomalies, and adversity for those who would rally the constitution around a unitary Britishness. “A neo-unionist nationalising project, predicated on a single over-arching identity,” he concludes, is unlikely to succeed. But this in no sense points to the immanent fragmentation of the Union into its constituent parts, he hastens to add: “Our constitutional predicament is altogether more complicated than that” (I, 559).

The addition of two concluding chapters on the “Constitution and Empire” casts the net even wider, dissecting a “British constitutional imaginary” that was inextricably bound up in imperial ambition (II, 468). The collection closes with the Colonial Office mandarin, Sir Charles Jeffries, in 1960 reflecting on the intricacies of devising new constitutions for so many former British territories, and wondering what the long-term implications might be for the status of Scotland, Wales, Northern Ireland, and even England itself in a new UK constitutional settlement. As with so many enduring entanglements of empire and modern Britain, the question remains a live one.

For practitioners of British Studies, these issues could hardly be more fundamental. Long overdue, this impressive collection brings fresh insight and urgency to questions that go to the very heart of the ever-changing conception of our subject.