Scotland voted in a referendum on Thursday to choose whether to end the 307-year-old union with England and become an independent nation or stay within the United Kingdom - a decision that could have consequences across the globe.
From remote highlands and islands to the tough city estates of Glasgow, people were almost equally divided over a vote watched closely by Britain's allies, investors and restive regions at home and abroad.
Pre-voting opinion polls gave the “No” campaign - those in favor of remaining in the United Kingdom - a slight edge. But hundreds of thousands of people still making up their minds held the key as polling stations opened.
Heart or head choice
Many people see the choice as one of “hearts or heads” - whether emotional stirrings and yearnings would outweigh pragmatic concerns over the risks and uncertainty that an independent state would face.
The issue has divided families and friends but also electrified this country of 5.3 million in months of debate.
Election officials expect turnout as high as 80 percent of the nearly 4.3 million registered voters.
"No" campaigners, husband and wife John and Christine Elliot, said they are optimistic of a win.
"If you add the fact that the bookmakers think that 'No' is going to win, then that is quite a powerful message, but you can not be complacent about it. The votes are there to be won,” John Elliot said.
Christine Elliot said, “Most of the polls have been the other way, even very small and of course the undecideds could swing it either way, but there has only been one poll that has put 'Yes' first."
She said she thinks there is a quiet majority of "No" voters who will swing the vote.
But her confidence is not matched by 22-year-old Matthew Wilson, who strides out of the polling station wearing a "Yes" badge.
"I have just spent a month in Europe and I was struck by how many people throughout Europe were switched onto all this,” Wilson said. “Everyone I spoke to (asked), ‘What are you voting, what is going to happen in the referendum?’ I told them it was just impossible to predict. But everyone was like, 'Come on Scotland, let us get your independence."
Wilson said he believes most young people are voting "Yes," a comment which was met with some disdain from Christine Elliot.
But, Wilson added,some people he knows may not like to admit they are voting "No" because it is not the popular choice among their friends.
'There's no going back'
On Edinburgh's main Princes Street, overlooked by a foreboding castle, “Better Together” campaigners handed out leaflets saying “Vote No.” “It's not worth the risk. There's no going back.”
Alex Salmond, the 59-year-old nationalist leader, told hundreds of supporters in Perth at a final rally: “Scotland's future must be in Scotland's hands.”
“This is our opportunity of a lifetime and we must seize it with both hands.”
The independence movement said Scots should be able to choose their own leaders and make their own decisions rather than be ruled from London. Supporters of the union said Scotland is more prosperous and secure as part of the United Kingdom and the ties that bind its peoples are too tight to be undone.
Salmond has said Queen Elizabeth should stay on as Queen of Scots. She has remained above the fray, in keeping with the constitution, but said on Sunday she hoped Scots would choose “carefully.”
Break up of United Kindgom
The prospect of breaking up the United Kingdom, the world's sixth-largest economy and a permanent member of the United Nations Security Council, has prompted citizens and allies alike to question what would be left, while the financiers of the City of London have warned of market turmoil.
British politicians, banks and businessmen have closed ranks to warn of economic hardship, job losses and investment flight should Scots decide to go it alone. Defense would also be a big question - Britain's submarine-borne nuclear arsenal, part of NATO's defenses - is based in Scotland's Firth of Clyde.
The United States has made clear it wants the United Kingdom, its main ally in Europe, to remain together.
“The UK is an extraordinary partner for America and a force for good in an unstable world. I hope it remains strong, robust and united,” U.S. President Barack Obama said.
The Scottish National Party has said it hopes to achieve full independence by 2016 if it wins and the result could encourage separatist movements around the world, starting with Catalans in Spain.
However, European leaders have warned that an independent Scotland would have to get to the back of the queue to join the European Union.
Many of those voting for independence felt rule from London had opened too wide a gap between rich and poor.
“I want a different kind of Scotland, a socially just Scotland,” said Lisa Clark, a church worker, after casting her vote for “Yes.”
However, National Health Service Dr. Charis Wong, 25, said she is quite happy to tell people she voted "No."
"I think ... if we vote 'Yes,' we do not have a clear plan to what the NHS (National Services Scotland) would be.The latest talk about the NHS cuts that will happen inevitably if the referendum goes on the 'Yes' side is quite worrying, so I think a 'No' vote would be safer for the NHS," Wong said.
Vote for independence
In the event of a vote for independence, Britain and Scotland would face 18 months of talks on how to carve up North Sea oil and what to do about EU membership.
British leaders accept that even if Scotland votes to keep the union, the United Kingdom's structure will have to change, as granting further powers to Scotland will provoke calls for a less centralized state from voters in England, Wales and Northern Ireland.
Some currency traders in London prepared to stay up all night to buy or sell sterling on the results of the vote.
Electoral officials said the result is expected by breakfast time on Friday morning, but partial results will give an indication of the trend after the count of major cities such as Glasgow are declared around 0400 GMT.
Edinburgh and Aberdeen, which with Glasgow make up nearly a quarter of the vote, are also expected around about that time.
Helicopters will fly from specially lit landing sites from remote islands to deliver ballot boxes to regional counting centers.
Marianne Brown contributed to this story from Edinburgh. Some material for this report came from AFP.