The Prime Minister and Scotland's First Minister have sealed a deal to grant the government in Edinburgh the power to hold a referendum on independence.
David Cameron and Alex Salmond signed the agreement during a meeting at the Scottish Government headquarters at St Andrews House.
The deal, which has been dubbed "The Edinburgh Agreement", follows months of negotiations. Private meetings between the two governments have covered contentious issues about the question on the paper.
Proposals for a second question on further devolution, short of independence, were firmly opposed by the UK Government. Negotiations between the governments were led by Deputy First Minister Nicola Sturgeon and Scottish Secretary Michael Moore.
Speaking after signing the deal, Mr Cameron told broadcasters: "I always wanted to show respect to the people of Scotland.
"They voted for a party that wanted to have a referendum. I've made that referendum possible and made sure it's decisive, it's legal and it's fair, and I think that's right for the people of Scotland."
Asked what he gets back when he has given Mr Salmond control of both the date and who votes, he replied: "What we have is what I always wanted, which is one single question, not two questions, not devo max, a very simple single question that has to be put before the end of 2014 so we end the uncertainty, we put beyond doubt Scotland's position either within the United Kingdom, as I hope, or separating itself from the United Kingdom, one single simple question.
"That for me was always the key. Now we've dealt with the process, now we should get on with the real argument, and I passionately believe Scotland will be better off with the United Kingdom but also crucially the United Kingdom will be better off with Scotland."