It has taken him a decade to get his hands on the top job, but where will Gordon Brown's famous 'moral compass' lead Britain, asks Frank Millar, London Editor.
Can Gordon Brown pull it off? The new British prime minister's plan is certainly audacious, and if it succeeds the end result will be acclaimed a sweet and highly personal victory.
However, he will need no reminding that the flip-side would see defeat depicted and experienced in terms of huge personal disaster. Michael Portillo observes that, with Tony Blair and Gordon Brown, Britain had a cabinet of two, whereas with Blair gone there is now a cabinet of just one.
There are no other big beasts around the table. However much he professes his disdain for the cult of personality in modern politics, for all purposes between now and the next election Brown is the Labour Party - and largely as a result of his own endeavours.
We all know - or thought we knew - the man who this week finally realised his lifelong ambition to become leader of the Labour Party. No matter that Brown originally supported the younger Blair to succeed the late John Smith. Or that Blair was the outstanding politician of his generation, a triple-election winner who took New Labour to an unprecedented second, then a third, term in office. The "TBGBs" of their brilliantly successful but explosive and often tortured relationship have been well chronicled through the years.
Brown quickly regretted his original reticence, and the resentment deepened when Blair failed to honour what Brown believed was a firm promise to stand aside in his favour soon after the second victory in 2001.
"There is nothing you could say to me now that I could ever believe," a bitter Brown reportedly told Blair in 2004. Ahead of the general election the following year Blair seemingly drew up plans to finally sack his troublesome chancellor. Too late; he found himself instead forced to recall Brown to the campaign frontline in the face of a widespread loss of "trust" in the government, principally over Iraq.
The rest, as they say - and as members of the "new government" would certainly have it - is history. The abortive coup last September. The consequent enforced timetable for Blair's departure. The long farewell and the failed attempt to find a Blairite standard-bearer - David Miliband, John Reid, Alan Johnson, Charles Clarke, Alan Milburn . . . anyone - to force a contest and block Brown's march on Number 10.
Perhaps a lucky Brown can escape the history. Despite all that went before, in the end he and Blair did manage to deliver the promised stable and orderly transition. Whatever about the voting public, Brown emphatically has Labour's mandate now. The former prime minister was apparently shown Thursday's list of cabinet appointments in advance and was satisfied that his friends and interests had been provided for. For a long time to come - and barring some radical repudiation of the Blair inheritance - the rest, the dispossessed, will simply have to keep their own counsel.
Yet that caveat tells us that Labour's recent history cannot yet be considered a closed book. And it directly informs the two big questions posed about the Brown succession, personal and political.
When Blair took power in 1997 he paid his debt for Brown's support in the 1994 leadership contest, conceding to his new chancellor unprecedented powers over great swathes of domestic policy. Brown exercised his muscle throughout Whitehall, earning a reputation among colleagues as a "control freak" and a bully. Nor was he any gentler in his treatment of Blair, as prime minister and also "first lord of the treasury".
Famed for often refusing to tell Blair what was in his budget statements, he once accused him of "stealing" one with a prior announcement about health spending. When Blair laughingly described Brown as a "big clunking fist" it was not at all clear he intended it as a compliment. Indeed, one cartoonist this week depicted the fist finally squashing Blair. Across Europe, likewise, Brown acquired a reputation for being arrogant, aloof and abrasive.
Yet suddenly, "Irn Broon" is presented as a smilingly collegiate chap, eager to restore cabinet government in "humble" service of the people, whose "trust" he will earn by ceding more power away from Whitehall. As a former colleague told the BBC's Panorama: "Brown doesn't do humble." In the run-up to this week's handover, moreover, some authoritative Whitehall commentators detected plans for a further concentration of power in the office of the prime minister.
Which is it? Can this big beast really change his spots? And what is he promising "change" to? And from?
Pressed by Jeremy Paxman on Wednesday's Newsnight, Brownite rising star Andy Burnham - now in cabinet as treasury chief secretary - struggled before suggesting the new prime minister would be a thinker for the long term and probably produce a 10-year plan.
But we've had 10 years of 10-year plans from this government, dominated as it has been across the range of domestic policy by the man who controlled the purse strings. We have been constantly reminded that most of Blair's big achievements were really down to Brown, from Bank of England independence, the minimum wage, millions lifted out of poverty, complicated tax credits for working families, and gentle redistribution through "stealth" taxation.
Blair and Brown presided over record spending in the quest for still-awaited "world-class" schools and hospitals, and chancellor Alistair Darling arrives just in time to find the spending options reduced against a backdrop of rising interest rates and growing concern about the scale of personal and family debt.
Did Brown hold back some pot of gold with which to liberate his own chancellor? As former Conservative leader Michael Howard asks, did Brown divine a whole set of policies that would be good for Britain but decline to share them with Blair? Pressed to identify the new challenges for the new era, Brownite ministers eagerly talk about the need for affordable housing - as if this was not an issue that pre- dated New Labour and is something they have been unaware of during 10 years in power.
In paying tribute to Blair's achievements, new ministers enthusiastically point to Northern Ireland and Africa rather than Iraq. However, if Iraq defines Blair's legacy, we know where Brown was. As Liberal Democrat leader Menzies "Ming" Campbell tartly reminds, he funded it to the tune of some £5 billion (€7.42bn).
Yet the appointments of David Miliband as foreign secretary and Douglas Alexander at overseas development - like that of Sir Mark (now Lord) Malloch Brown, a former UN deputy secretary- general, one-time spokesman for Kofi Annan and outspoken critic of the "war on terror", now minister for Africa, Asia and the UN - carry the whiff of change in British foreign policy.
Brown may have it relatively easy over Iraq, where a review of US policy in September could facilitate the draw-down of British troops already announced by Blair. Brown will also not be required to have the same relationship with president George W Bush in the second half of his second and final term in the White House. However, Afghanistan represents a huge and seemingly growing British military commitment still receiving comparatively little attention here.
The problem of Iran hasn't gone away. Nor, as the discovery of a viable bomb near Piccadilly Circus in the early hours of yesterday reminds us, has the terrorist threat.
Alas, it may be in this context that we first discover what, if anything, is "new" about the Brown government.
Miliband may assuage doubts with talk of a "diplomacy that is patient as well as purposeful, which listens as well as leads". However, if Labour left-winger Diane Abbott is correct, we will soon discover that new home secretary Jacqui Smith "is not a soggy libertarian".
When Brown invited Lord Ashdown to join his government, this was offered as evidence of the new prime minister's commitment to reach beyond narrow party interests. Leading Liberal Democrats, on the other hand, detected "low politics" and a readiness to divide and conquer, with Brown putting the careerist cart before the policy horse in respect of ID cards, 90-day detention for terror suspects, the surveillance state and the erosion of ancient liberties.
They were almost certainly right. Mr Brown is doubtless directed by his famous "moral compass". But he has been relentless in his pursuit of power, as he will be ruthless in his campaign to keep it. From Brown's first foray into "non-tribal" politics, his opponents should consider themselves warned.