I grew up in a house called Rhodesia.
The name was picked out in shaded glass above the imposing front door. The house beside it had been called Transvaal.
“Where’s the Orange Free State?” one of my school friends quipped once. “Across the street?”
I loved the exotic stamp of it, that our solid brick home, built against the damp climate of south-west Scotland, carried in its name the allure of some distant sunlit place on the other side of the world.
How did it come about? Those houses had been built, 70 years before we moved in, by a local man who’d spent his working life in the colonial service in southern Africa and who’d come home to retire.
The British Empire had vanished by the 1970s, but only recently, and the memory of it was a powerful living thing.
We Scots, we were taught in schools, had benefited disproportionately from it; for while the English may have ruled the Empire, the Scots, for sure, had run it.
In October 1974, at the first general election of which I have a clear memory, the Scottish National Party won 11 seats in Scotland.
One of them was Galloway, where we lived, and which had, until then, been a safe Conservative seat.
We lived in a house whose name celebrated the projection of British power across the globe - and now we had an MP who wanted Scotland to breakaway from Britain.
The SNP had won seats before. Winnie Ewing had famously taken the former Labour seat of Hamilton at a by-election in 1967 and had gone off to Westminster promising “Scotland Free by 73”.
Margo MacDonald, the popular and charismatic blonde bombshell who would become a commanding figure in Scottish politics for four decades, had stormed another Labour stronghold, Glasgow Govan, in 1973, only to lose it at the general election a few months later.
But now there were 11 SNP MPs at Westminster and they were there not just - like others on the opposition benches - to dispute the policies of the government of the day, but to challenge something most in Scotland had taken for granted as beyond question - the legitimacy of the British state itself.
Back then my grandparents were still of working age. They had grown up in the early 20th Century. Their frames of reference were not just British but imperial.
The United Kingdom still, as it had throughout its history, preferred the wide-open seas to the entanglements of European alliances. When my grandparents thought of the world, they thought not of Paris and Berlin and Brussels and Rome, but of Singapore and Bombay and Durban and Melbourne.
To them - to most of their generation - the idea of dismantling the state on which this greatest of empires was founded seemed eccentric, even perverse - the unrealisable, even reckless, dream of a romantic fringe.
What has happened in the past four decades to transform the question of Scottish independence? How did a fringe preoccupation come to occupy the centre ground of Scottish politics, so much so that even its fiercest opponents no longer argue that Scotland couldn’t survive as an independent state? How did independence become a credible mainstream ambition, embraced not just by nationalists but by many on the traditional (non-nationalist) centre-left?
It is in part demographically driven, a consequence of the dramatic changes that have reshaped the economic topography of Scotland, the UK and the wider world over the course of those years.
In the world that my grandparents knew and understood, Scotland, like the rest of Britain, was locked into a vast global trading bloc that preferred to haul frozen lamb and butter half way round the world from New Zealand than buy the same products from neighbouring France; that imported dried fruits from Australia rather than from the countries of the Mediterranean.
It was a trading system based on protective tariffs and trade barriers known as Imperial Preference. Britain chose to trade with the old “kith and kin” territories of the English-speaking world rather than with its European neighbours.
The Empire, the powerful, binding economic force of it, had, for generations, given Britons a common purpose, an enormous shared enterprise. It gave Scottish merchants access to trade with all the continents. The city of Glasgow, before its days as an industrial powerhouse, was built on trade - sugar and tobacco in particular.
Walk along the banks of the Clyde and the ghosts of that past are written into the place names: India Quay, Jamaica Street, Durban Avenue. Pacific Quay, where BBC Scotland now has its headquarters, was once Plantation Quay, a name that recalls a past that Scotland prefers to forget - its role in the trans-Atlantic slave trade.
But by 1974 the Empire was gone. Imperial Preference was gone. When Britain joined the European Economic Community in 1973, many of its old trading partners around the world - especially Australia and New Zealand - regarded it as a betrayal. The former British dominions and colonies had to seek new markets and new trading partners, as Britain turned its face away from them to embrace a new European identity.
The Empire became the Commonwealth, a community not of real economic might but of shared memory, of common values, of fellow feeling - in essence a community of sentiment, powerful sentiment maybe, but of sentiment nonetheless.
Did my grandparents’ generation feel diminished by this loss of stature in the world? Yes, I think they did, even personally so. The US Secretary of State Dean Acheson famously said Britain “had lost an empire and had yet to find a role”.
In the 1970s, politics seemed preoccupied with the management of national decline. In my first year as an undergraduate at Edinburgh University, as the Winter of Discontent took hold, we debated in our politics class, whether Britain had become “ungovernable”.
It was in that context that the SNP emerged as a new force in electoral politics.
If the glue of British union for my grandparents had been the common enterprise of empire, for my parents, born in the 1930s, it was no less strong. They came of age as the Empire was dying, but they lived as children through World War Two and the shared effort, and shared risks, of total war.
In the summer of 1940, at the start of the Battle of Britain, Winston Churchill told the UK it would have to “stand alone” in the breach. Other European countries were falling to the Nazis, compromising with them, or anxiously keeping their distance by declaring neutrality.
In 1945, Britain emerged from the conflict with a moral stature unequalled across the continent. This, too, that generation shared, and Britain continues to celebrate it, in ritualised memory and in popular culture, 70 years on - in Scotland as enthusiastically as anywhere else in the UK.
That generation was also bound together by what came after the war. The welfare state that the Attlee government built was another great shared British enterprise. The NHS, state pensions, child benefits, free education, increased social mobility - this was the Britain my parents inherited as young adults and it, like the Empire before it, had been a truly British enterprise.
And this is the world into which my generation was born and in which we grew into early adulthood.
Goodbye to the past
Empire, Commonwealth, the memory of the war, the Attlee settlement, the welfare state. At the end of the 1970s, when I was becoming politically aware, the “political space” - the “demos” - most Scots thought and argued in was still, it seemed to me, emphatically British.
The idea of an independent Scotland, the SNP’s 11 Westminster MPs notwithstanding, was still a minority enthusiasm. The first vote I cast in my life was in the 1979 devolution referendum, which proposed the setting up of a Scottish assembly.
The campaign was lacklustre and uninspired. One in three Scots voted for it; one in three against; one in three stayed at home. The idea, back then, that Scotland needed a legislative parliament to take charge of its own domestic affairs, failed to take hold.
Imagine a Caledonian Rip Van Winkle waking up from a 20-year sleep that had begun on the eve of that first referendum in March 1979. He would open his eyes on a social, economic and political landscape that would be almost unrecognisable to him.
Two things have happened: first, there is a Scottish parliament with primary legislative power (something that wasn’t even proposed when his sleep began) which has quickly established itself as the undisputed centre of public life in Scotland; and second, much of what it had meant to be British in Scotland has been eroded or swept away altogether.
The result is a long slow process by which a distinct Scottish demos has emerged within the British political space.
When I was a teenager in Scotland, Britain - and indeed the British state - counted for a great deal.
The British state dug coal. It milled steel. It built ships.
It manufactured motorcars and motorcycles. It employed much of the industrial workforce in the publicly owned industries that did all these things.
The British state supplied the electricity that lit your home and the gas you cooked with. The GPO didn’t only deliver your mail; it put the phone in your hall.
Now these things, if they are done at all, are done by the market. And the market is not British; it is global.
Just outside Edinburgh, at Newtongrange in Midlothian, there is a museum that tells a story that is intimately linked to this long, slow transformation.
The Scottish Mining Museum sits on the site of the old Lady Victoria Colliery. It has preserved the surface buildings of a pit that was opened in 1895 and closed in 1981.
You can inspect the winding gear that once lowered thousands of men every day into the bowels of the earth, you can see the engineering kit that brought countless tons of coal to the surface every day for a century, and you can examine the daily lives of those who toiled here for so many generations.
Much of the ground around the old pithead is strewn with massive rusting metal machine parts, like a vast industrial graveyard.
But you also get a clear sense of the pride that once prevailed in the community the mine sustained.
And the point is this - if you were a miner in Midlothian, or Ayrshire, or Fife, you belonged to a community of shared interest with miners in Nottinghamshire, Yorkshire and South Wales.
You inherited the same prevailing industrial narrative - the struggle for social justice, improvements in workplace conditions, working hours, fairer wages. You marched behind the same banners, honoured the same pantheon of Labour leaders and working-class heroes who had led the struggle for betterment.
There was little, in this powerful identity, that distinguished Scottish miners from their English and Welsh counterparts.
The enterprise - the experience - was shared; it was British.
Those communities were bedrocks of British identity in Scotland. And not just in mining - in all the heavy industries that had shaped the Scottish economy since the 19th Century.
Those communities were tough places for SNP candidates in those days. We work for something called “British Steel”, voters would say; it pays our wages, our annual leave, our pensions; our factories are integrated with and depend on production in plants elsewhere in the UK - are you going to unpick all of that?
The deindustrialisation of the 1980s might well have been the dramatic (and painful) end of a long and inevitable period of industrial decline. But one of its unintended consequences was that these communities were, in effect, dispersed, and with each year that passes, the memory of the shared British endeavour which sustained them fades further into the middle distance of collective memory.
In 1979, at the election that brought Margaret Thatcher to power, one in three Scots voted for the Conservatives, returning 22 Scottish Tory MPs.
By 1987, this was down to one in five voters and only 10 MPs out of the 72 Scotland returned to Westminster.
By 1992, Scotland had voted decisively against Conservative governments four consecutive times, and on each occasion a Conservative government in Westminster installed a team of Conservative ministers at St Andrews House in Edinburgh to govern Scotland.
Though the SNP were still not a serious electoral threat to the main parties - even as late as 1992 the Conservatives still beat the nationalists into third place in the popular vote - politics in this decade acquired its much more powerful Scottish flavour.
Opposition MPs and grassroots activists began to talk of the “democratic deficit”. The “no mandate” argument gained popular traction - the idea that the Conservatives had no democratic right to govern north of the border, and that Conservative policies that had electoral support in England were being “imposed” in Scotland where they had been repeatedly rejected.
The Scottish historian Sir Tom Devine has argued that this period saw the greatest challenge to the legitimacy of the British state, and to the sovereignty of the Westminster Parliament, since the Jacobite Rebellions of the 18th Century.
This is the difference between that lacklustre devolution campaign of 1979, in which Scotland could not muster sufficient enthusiasm for a weak national assembly that had few legislative powers, and 1997, when Scotland voted for the parliament it now has.
By the 1990s, there was an entrenched popular consensus in favour of home rule.
It was, arguably, a change of heart in the Labour Party that made the difference. The Labour MP, Robin Cook, later to become foreign secretary, was MP in the constituency in which I lived.
In 1979, like many Labour people, he was adamantly opposed to devolution, arguing that social solidarity didn’t stop at the border; that the real divide in British society was not between England and Scotland, but between rich and poor.
Glasgow’s Billy Connolly used to say something similar - that he, having worked in the Glasgow shipyards, had more in common with a shipyard welder in Portsmouth or Liverpool than he did with a highland landowner.
That argument had traction among Labour voters then; less so now when the number of shipyard welders working anywhere has plummeted so dramatically.
Robin Cook’s moment of epiphany came when Labour suffered its third successive general election defeat in 1987. By the end of the 1980s, all but a minority in the Labour Party were in favour.
The MP Tam Dalyell was one. When I went to see him in the early days of the independence campaign he reiterated the view he had held in 1997 - that a devolved Scottish parliament would be the first step on the road to independence.
“It’s never good in politics to say ‘I told you so’, but I jolly well did!” he told me.
But the majority Labour view was that a strong Scottish parliament within the UK would see off the SNP as an electoral threat. The late John Smith, Labour leader from 1992 until his unexpectedly early death in 1994, said devolution would represent the “settled will” of the Scottish people. George Robertson, later defence secretary and secretary general of Nato, said it would “kill nationalism stone dead”.
But it didn’t. The SNP did not lie down and die.
They got stronger. They won the Holyrood election in 2007, ousting a Labour Party that had won every previous election in Scotland for half a century. And then, in 2011, the Nationalists astonished even themselves by winning an overall majority in the Scottish parliament - something that not even mighty Scottish Labour had achieved.
In 2012, a year after that stunning SNP victory, the Conservative-Liberal Democrat government at Westminster passed a bill strengthening the competencies of the Scottish Parliament, by transferring some tax-raising powers to Holyrood.
They were described as the greatest transfer of sovereignty between London and Edinburgh in 300 years. Those changes are not due to come into effect until 2016, and already they are out of date.
Just 15 years after the first Scottish parliament in 300 years sat in Edinburgh, all three main parties at Westminster are promising much more, with the Conservatives, who had opposed devolution for decades, offering to devolve all income tax raising to Scotland.
Why? Is this too designed to “kill nationalism stone dead”? The Scottish Tory leader Ruth Davidson fought her leadership election campaign promising to oppose further devolution, saying she would draw a “line in the sand”. She changed her mind earlier this year, as the independence campaign took off - and persuaded David Cameron to back change on the grounds that it would make the Scottish Parliament responsible for raising public money as well as spending it.
She has a point. For 15 years the Scottish Parliament has been a fiscally lopsided institution. The money comes from a block grant from the UK Treasury. Westminster decides how much tax we all pay and how much government there should be in relation to the economy but not how it’s spent.
You can see why there’s little room in the Scottish national discourse for a party that says “vote for us and we’ll cut your taxes; vote for us and we’ll make government smaller”.
Transferring tax-raising powers is, for David Cameron now, a way to make the Scottish Parliament more fiscally responsible and in that sense Tory values and Home Rule values have converged to change policy for the first time in the party’s long engagement with this question.
So in a sense, whatever the result this September, the moderate nationalists, those who have always taken a gradualist approach, have already won something. For them, the long-term direction of travel is clear. The Scottish Parliament will soon be much more powerful than anyone at Westminster (except the SNP) intended in 1997.
Why has this happened? Why did it not “kill nationalism stone dead”? Part of the answer lies in what has happened to the Labour vote, once solidly dependable.
Polling evidence suggests most Labour voters will reject independence. But privately, Labour activists know that between one in two, and one in three, of their traditional voters have already decided to vote yes.
I left Scotland nearly 30 years ago to pursue (like many young Scots had to) a career first in London and then abroad.
Many of my old friends from the 1980s were drawn into the Labour fold by the swiftness and, as they saw it, unnecessary brutality, of the economic and social changes that were sweeping Britain, and Scotland in particular.
Now that I have come back, I find many of them declaring themselves as supporters of independence. For some of them it has been a reluctant and painful conversion.
I asked one, an old friend I hadn’t seen for at least 10 years, why he’d be voting yes. “I changed my mind quite a while ago. For me it’s about the way Britain has gone - the extremes of wealth and poverty that people down south seem comfortable with, the dominance of the privately educated people in all walks of life, the rise of UKIP, the talk of leaving the EU and a Labour Party that I don’t really recognise any more”.
He is not alone. Social attitudes surveys reveal that Scottish public opinion, on any given question, is not very different to opinion elsewhere in the UK. The Scots do not seem to be more left-wing, issue-by-issue, than anyone else - at least not by very much.
Why, then, do the Scots vote so differently? Why is it that the central Edinburgh constituency that I live in returns a Labour MP dependably at every general election? When I moved here in the 1970s and 80s, it was a Tory seat and Edinburgh was mostly a Tory city.
The yes-supporting journalist and writer George Kerevan has himself moved from the British left to the independence camp.
The need for independence as he sees it is “based on the need to put into practice traditional Scottish views on morality inherited from the Reformation and codified by the Scottish Enlightenment… This is a moral philosophy that definitely encourages private endeavour rather than state paternalism, but it also anchors private morality in a social context".
In other words, private endeavour and reward should be connected in some way to the greater public good.
For nationalist intellectuals who have, in the course of their lifetimes moved to the independence camp, what is happening in Scotland is, in part, a Presbyterian revolt against what they perceive as the growing inequality of British society - the apparent retreat from the ideals of social mobility, from the social justice agenda that characterised post-war Britain from the 40s to the 80s.
There is clearly an appeal to some Labour voters that an independent Scotland could be a fairer, more just society; it is striking to me how often that is articulated by yes campaigners, much more than talk of the flag, or national identity.
How serious a threat is this to the Union, even if the anti-independence case, as the polling suggests, wins this September?
One view is that the long-term direction of travel is clear and that independence will, one day, happen in a series of increments. Privately, Labour activists concede that that is something that they will need to address in the years ahead if they win.
But there is another view, much more optimistic from the anti-independence point of view, that says 2014 is the high water mark of the independence aspiration that has been bubbling since the 1980s.
“It’s your generation of Labour voters, Allan,” one young Labour activist told me, implying that this disloyalty to Labour is largely confined to those with adult memories of the Thatcher years.
“It’s not my generation. When next will the Nationalists’ stars align so perfectly - an SNP majority at Holyrood, a Tory-led government at Westminster, the generation that came of age during the difficult and polarising Thatcher premiership still active and still angry?” he said.
“The pro-independence Labour vote,” another activist said, “is middle-aged, scunnered, and male." This, he said, is its last chance.
Maybe so. But what is the glue that holds the Union together now? And how does it compare to the power of empire, the experience of World War Two, the building of the post-war state?
What remains of Britishness now remains substantial - the shared monarchy, the armed forces, the BBC, popular culture in general, and, crucially, the pound sterling.
That - and the enduring sentiment of Britishness - might well be more than enough to swing it this time. But is it enough indefinitely?
In that sense, the medium to long term, the enduring survival of the Union is a matter for the whole United Kingdom and for Westminster in particular.
Whichever way the vote goes, there can be no going back to business as usual.
The United Kingdom will have changed.