Alex Salmond chose the grand surroundings of Edinburgh Castle to expand on his dream of Scotland re-establishing itself as anindependent nation.
He insisted a positive argument for independence would win, despite polls showing only minority support.
After delivering his statement to the Scottish Parliament, he took the short trip up the historic Royal Mile to the ancient castle above the capital city.
Press and broadcasters from around the world – from New Zealand, to Azerbaijan – packed into the Great Hall to question the First Minister on his plan, touching on the international dimension.
For example, was he concerned that Spain could veto Scotland’s role in the European Union? Would Scotland choose to align itself closer to Scandinavian countries?
And would poet Robert Burns approve of the plan? He would, the First Minister said.
In a short speech, Mr Salmond said: “Where better than the Great Hall of Edinburgh Castle to launch the great debate on Scotland’s future.
“This historic place, in the context of the build-up to Scotland’s referendum, involves both the past, the present but above all the future.
“It was in this venue, Edinburgh Castle, that the first recorded venue of the old Scots parliament was held almost 900 years ago.
“This hall itself was built by James IV, Scotland’s renaissance king, about 500 years ago.
“It does stress the continuity of Scotland as an ancient, historic nation stretching back over a thousand years of independence before the Act of Union of 1707.”
The hall, in the heart of the castle, is steeped in history. Stained glass windows contain names such as William Wallace and Robert the Bruce.
The choice of venue angered the Scottish Labour and the Conservative parties, who complained that the national location was being used for partisan purposes.
Mr Salmond said that Scotland should be able to take charge of its future, outside of the United Kingdom.
Holyrood already takes responsibility for education, justice and health, but does not raise all its own funds, relying on a large block grant from England.
Mr Cameron said: “We look to the future of the Scotland that we seek. The Scotland that will be the subject of the key debate that unveils over the next two years and more.
“We see a Scotland that is proud of its heritage but is always looking to the future.”
Addressing the international audience, he said the quest for independence had been peaceful.
“We offer malice towards nobody, we offer friendship towards all – particularly those other nations in these islands – but across the European continent and beyond,” he said.
“We seek to play a responsible role in the international community of nations.”
He added: “This has been, over 100 years or more, an entirely democratic process - not a single person has lost their life arguing for or against Scottish independence.
“There hasn’t been so much as a nose bleed.”
Facing questions, he said an independent Scotland would remain close to the rest of the United Kingdom, that the country would become an EU state on the same terms as England, and that there was still room for a second question on achieving maximum powers under devolution.
Asked if countries such as Spain, which has its own separatist movements, might block Scotland’s integration as an EU member state, Mr Salmond said: “We must always be aware of mischief-making by our political opponents who may want to ascribe to other people views which are actually held by themselves”.
“A positive vision of the future is key to winning the referendum campaign,” he said.