Train travel in the mourning period for the Queen is likely to be "extremely busy", the rail operator warns.

It wasn’t exactly a shock. The ancient and beloved Queen, who had reigned much longer than most of her subjects had lived, was 96 and visibly failing. Leaning on a stick, she managed a smile last week as she invited Liz Truss, Britain’s new prime minister, to form a government. And within 48 hours, she was dead.

A huge and complex contraption of official mourning, rehearsed to exhaustion over the past 15 years, lurched into action. Public events were canceled. The media uncorked a day-and-night flow of solemn eulogy and familiar images. Rain fell, cold and heavy, on Londoners gathering with umbrellas outside Buckingham Palace. Before the announcement, nobody could imagine—wanted to imagine—quite how they would feel. But when it came, they felt only a slow, numbing sadness, and fear.

Elizabeth II’s life and reign had formed a sort of weatherproof awning, sheltering a long carpet of years. This carpet of continuity led all the way back to the Second World War, to the foundation myth of modern Britain, when “we stood alone” against fascism. Now that carpet is being rolled up. The Queen and her kingdom were pictured as almost unchanging through those 70 years on the throne. But today her subjects look around and admit that, in reality, almost everything had been changing all through her reign. And they ask themselves: Are we the same people?

In a sense, the Queen did little. She traveled indefatigably, smiling and encouraging, but unlike most of her forebears, she sought no political agency. Instead, she invaded and colonized imaginations. Up to a third of the British population (including anti-monarchists) has confessed to dreaming about her; typically, she drops in for a cup of tea to ask you—such a relief to be talking to a normal, sensible person!—what to do about her children or her savings or her garden. As the Scottish philosopher Tom Nairn has written, she has been an “enchanted glass,” a mirror in which her subjects see themselves reflected as united, brave, and kindly, loved and respected by the giant spread of the outside world that was once the empire and is now the Commonwealth.

[Read: No one performed Britishness better than Her Majesty]

That was what the British were encouraged to see in 1952, when this beguiling young woman ascended to the throne and a “new Elizabethan age” was proclaimed. But nothing of that sort followed. The first Elizabeth had launched English colonists and conquerors across the oceans. The second Elizabeth had to sit and watch Great Britain diminish in the world, as its colonies struggled to their feet and marched off to independence. That enchanted glass has turned out to be a distorting mirror. But the Queen projected a calm assurance that nothing had really changed, that Britain was still the same world-leading, stable old country that had emerged after the defeat of Hitler. This soothing story has kept her people comforting themselves in that false reflection.

With her passing, the deepest-laid question is exposed: What is Britain?

Elizabeth II kept Britain going, in the sense that English people, who comprise roughly 80 percent of Britain’s population, looked into her mirror and saw a multiple United Kingdom, a nation whose “family” (to use her word) reached across distant continents and oceans. But to many Scottish or Welsh people, England, Scotland, and Wales are the nations, and the U.K. is the state that incorporates them. The Crown itself has helped disguise an often overbearing Englishness as British. And with the Queen’s departure, the fissures papered over by this mystification of an overarching British identity are bound to widen.

During the latter part of her reign, Elizabeth was unable to hide her anxiety over the growing movement for Scottish independence. Even the grant of devolved autonomy to Scotland and Wales in 1999, which gave each its own national Parliament with limited powers, was known to worry her. Her subsequent joy that the Scots narrowly rejected independence in the 2014 referendum also became public. Now, however, the political tensions gradually pulling the United Kingdom apart have no plausible image maker to restrain them.

In her person, Elizabeth bore up a tradition of English aristocratic culture—horses, dogs, country houses, a shooting estate in the Scottish Highlands—that is rapidly dying out (and with which her son King Charles III seems uncomfortable). But she proved to be far more than the epitome of posh. Decades ago, she managed to subdue her peculiar 1930s upper-class accent (“hice” for house, “ket” for cat), which was inviting mockery. Endlessly patient and empathetic as she shook a million hands and asked a million kindly questions, she could be coldly intolerant when members of the royal family showed bad manners or succumbed to emotional crises or, worse, scandal.

The limit to her capacity or willingness to extend sympathy brought the most dangerous moment of her reign in 1997, when Princess Diana was killed and the Queen declined (at first) to return from her Scottish holiday. For a few days, the passionate crowds burying the memory of their “People’s Princess” in heaps of bouquets and soft toys condemned the monarchy for unfeeling arrogance. But beyond that moral severity, the Queen could be high-spirited, even sharply witty. (When a courtier suggested that she was giving TV cameras too much access to her private life, she retorted: “I have to be seen to be believed!”). Seventy years of Privy Council meetings and discussions with 15 successive prime ministers gave her—so her visitors discreetly hinted—an unmatched store of political experience and wisdom.

[David Frum: How she did it]

A pity for historians that those conversations could not be recorded—and perhaps that we cannot be sure which prime ministers she liked best. Margaret Thatcher clearly grated on her. Insofar as the Queen’s political views were discernible, they seem to have been close to an old-fashioned, “one nation” caring conservatism rather than the neoliberal dogmas that captured the Tory Party.

Initially, little will change. The new King Charles III faces months of gaudy English pageantry—heralds trumpeting, golden state coaches, full-dress military parades, a funeral, a coronation—before he can get down to work. He has made an unexpectedly confident start, but, despite dalliances with environmental issues and the like, he is hardly the rebel. He is unlikely to separate the monarchy from its bizarre financial, legal, and constitutional privileges, which include exemption from laws affecting royal income or estates and the right—long disused but still on the books—to fire a government. The Queen’s reign was—for England, above all—a long, tranquilizing slumber. But waking up, a far less deferential people, far more willing to challenge power, faces two linked emergencies.

One is territorial; the other is constitutional. First, King Charles’s United Kingdom shows signs of breaking up. The national assemblies in Scotland and Wales—the former ruled by a Scottish National Party majority, the latter by a Labour Party one—have been overruled for more than decade by Tory governments in London that owe their electoral mandate to the U.K.’s English populace. This is not a sustainable partnership, and the independence movements grow stronger. In Northern Ireland, the recent electoral victory of the nationalist Sinn Fein party is an indication that, sooner or later, the province will probably quit the United Kingdom for a united Ireland (and for membership in the European Union). The last time a British monarch truly intervened in politics was over this very Irish question, when in 1921 the late Queen’s grandfather George V pushed the British government into ending the bloodshed in Ireland and opening negotiations for an independent Free State.

Britain’s unwritten constitution is profoundly monarchical—not because a hereditary king or queen is head of state but because it embodies an antique idea of absolute authority. After the Glorious Revolution of 1688, England overthrew royal absolutism—ending, once and for all, the supposed “divine right of kings”—but then transferred that absolute power to Parliament. The archaic English doctrine of parliamentary sovereignty means that, in theory, a prime minister with a House of Commons majority can impose their will, unhindered by any bill of rights.

[Read: The second Elizabethan age has ended]

The Enlightenment concept of popular sovereignty, of power leased upward from below, is alien to English-dominated British governance. Power in this old country still flows from the top down. The system is almost designed for tyrants, yet politicians over the years have hung democratic drapery (universal suffrage, free speech, independent judiciary) over this autocratic armature. Today, that compromise is looking threadbare. A less reflexively respectful generation has watched recent British governments trample over the conventions supposed to constrain executive power, most conspicuously during the Brexit debates, when Boris Johnson illegally attempted to shut down Parliament with a “prorogation.”

The Elizabethan years assured the people that Britain remained a good, sound country, in spite of many a crisis, under the blessing of its monarchy. They are no longer so sure. They want more rights, more control, less advice to be quiet and keep believing. For the moment, a rock-solid residue of faith in the House of Windsor abides, especially in England. But when the tide of grief recedes, in dire economic times, royal privilege and royalty itself will be questioned, starting at the United Kingdom’s periphery and working inward.

Elizabeth II tried to preserve the mystery cult of the Crown but ended up being loved and revered for the person she was. Dangerous! The mirror of monarchy then loses its enchantment. If the symbols of the sovereign matter less than the mortal who wears them, Charles III will reign unprotected except by his own merits. If he or a successor stumbles and falls, the Crown—the monarchy itself—might fall with them.

Shortly after being officially proclaimed King, Charles III, took the time to greet those who came to offer their support to the new sovereign in London on Saturday.