Following Barbados's transition to republic status in November 2021, there remain fifteen so-called Commonwealth realms of which the British monarch is sovereign. In all but one of those—the United Kingdom itself—King Charles is represented by a governor-general who fulfils the conventional duties of a constitutional monarch in his absence. As H. Kumarasingham, the editor of the excellent collection of essays, Viceregalism: The Crown as Head of State in Political Crises in the Postwar Commonwealth, notes, at one time or another, Charles's mother, Queen Elizabeth II, had been head of state of thirty-two independent countries around the globe. Barbados has recently been added to a list of seventeen states, including Pakistan, Ceylon, Ghana, and Trinidad and Tobago, which were granted independence as realms before making the transition to republics. That list does not include India, which made the relatively swift (1947–1950) move from realm to republic under Queen Elizabeth's father, George VI, thus setting the precedent that the Commonwealth was prepared to accommodate countries that did not recognize the king as their sovereign. The subject of the role of the monarch or their vice-regal representative in the post–World War II era is one with a wide geographical reach.

This reach is not confined to the countries mentioned above. An extremely useful contribution in Kumarasingham's collection is that provided by Andrew Harding, who considers the extent to which Malaysia—which has a sovereign chosen in rotation from the traditional rulers who head nine of the country's thirteen states—broadly follows the conventions that operate in the Commonwealth's other constitutional monarchies. Kevin Y. L. Tan, looks at the problems of reforming the indigenous monarchy in the Commonwealth state of Brunei Darussalam. In the first of two separate chapters, Donal Lowry discusses the role of the governor of Northern Ireland who presided over the province from partition in 1920 to the departure of Lord Grey in 1973 in the wake of the imposition of direct rule. In the other chapter, Lowry traces the role of the governor of Southern Rhodesia, which enjoyed a sort of quasi-Dominion status from the 1920s, designed to placate the political ambitions of the territory's dominant white minority.

As press coverage repeatedly demonstrates, the functioning of the realms and their relationship to the broader Commonwealth are poorly understood. This is in large part because the system is so complex and no single constitutional instruction manual exists. The reader is thrust into these complexities by Kumarasingham's opening chapter, in which he considers “the Head of State as a political actor during crises” (2) in areas where the conventions governing a largely nonexecutive head might be said to apply. Indeed, this is the organizing theme of the collection as a whole. But the reader is immediately confronted by the problem of definitions. Who precisely is the head of state in the Commonwealth realms? To some extent, monarchists in the realms (as Mark McKenna notes in his chapter on Australia since 1975) have tried to have it both ways, defending the existence of an absentee sovereign while often insisting that their de facto head of state is the governor-general, invariably now a person local to the country concerned. And even if the definition of head of state embraced both the monarch and their governors-general, how to describe their role? As Kumarasingham notes, it is misleading to describe them as merely “ceremonial” (3) or even as “non-executive” because they retain significant prerogative or reserve powers.

The interrelated themes of the nature of political power and the basis of political legitimacy help to bind together this highly accomplished collection of case studies. In place of Walter Bagehot's famous enumeration of the three rights of the British monarch—to be consulted, to encourage, and to warn—Kumarasingham presents three “rights and options” (16) available to a postcolonial head of state: “the right to rule, the right to uphold and the right to oblige” (the latter implying that they facilitate rather than imposing restrictions upon the actions of the governing party) (30–35). Parliamentary democracy implies that power is effectively exercised temporarily by the government of the day for as long as they retain the confidence of the electorate. And in a constitutional monarchy, the font and custodian of that power is the head of state rather than the head of government. As Kumarasingham notes (3), Vernon Bogdanor's concise description of the British constitution, “What the Queen in parliament enacts is law,” encapsulates the idea of the monarch as a sort of battery of legitimacy powering the parliamentary system. This is the third of Kumarasingham's rights and options for the head of state, a fairly passive process of making their power available to the head of government.

In a more proactive sense, the head of state is also the custodian of the constitution (Kumarasingham's “right to uphold” [23]) and in extremis they have the authority to make a decisive intervention to break a constitutional logjam or even to govern directly (“the right to rule” [17]). Yet in ordinary circumstances, the Crown's legitimacy is not sufficiently robust or unquestioned to render decisive actions risk free. The glaring anomaly of retaining an absentee head of state has meant that perhaps the most accurate description of its political status in most of the realms is that it is tolerated. In the case of Australia, the conventional view of the constitutional crisis in Australia in 1975 when the governor-general, Sir John Kerr, dismissed Labor prime minister Edward Gough Whitlam, is that it made a significant dent in the Australian public's inclination to tolerate and trust a neo-imperial viceroy. While Kerr himself expressed the view that it was “no bad thing” the Australian public “should have been reminded that the Crown possessed reserve powers” (19), McKenna suggests the accusation that Kerr acted in a partisan manner has haunted the office of governor-general ever since. Anne Twomey, ostensibly writing about the tiny Realm of Tuvalu, provides a fascinating take on the Kerr affair by describing the far more sensitive and nimble way in which the island's governor-general, Sir Iakoba Italeli, resolved a comparable constitutional crisis in 2013 without bringing his office into disrepute.

In terms of the extent to which viceregalism is tolerated in the realms, the world has witnessed a distinct change of gear in the Caribbean since the book's publication in 2020. A combination of factors, including the Black Lives Matter protests, the Windrush scandal in the United Kingdom, and the growing movement demanding reparations for slavery and colonialism have encouraged a series of Caribbean leaders to make concrete promises about moving their countries to republic status. If the Caribbean realms fall like so many dominoes in the years to come, however, future historians are unlikely to pin the blame on particular governors-general. Kate Quinn's essay on the Caribbean points to the significance of distinct national political cultures across the region in determining the way in which the office of governor-general is viewed. In some, like St. Lucia, governors-general have been caught up in repeated controversies over their political allegiances, whereas in others, like Jamaica, there has been a greater tendency to regard the office as being above party politics. Because developments in the Caribbean are likely to keep the realms in the news over the next few years, Viceregalism is all the more timely. Kumarasingham and his contributors have produced a volume that is not only of considerable scholarly importance but also of great practical value to those currently charged with navigating these murky constitutional waters.