(CNN) — A simple yes or no question will be on the ballot: Should Scotland be an independent country?
A decision that will have major implications on the centuries old union between Scotland and rest of the UK.
What we know as modern Scotland was formed in the 13th century, when England and Scotland signed the Treaty of York, mapping out Scotland’s southern border.
Sixty years later the countries were at war with the legendary Scottish rebel William Wallace helping to lead the charge.
Wallace’s fight for freedom was the subject of Hollywood blockbuster Braveheart.
Years of war paid off for Scotland.
In 1328, England recognized Scottish independence in the Treaty of Northampton
In 1603, Queen Elizabeth, the last of the Tudors died at age 69.
And that cleared the way for King James the Sixth of Scotland, son of Mary Queen of Scots to become England’s king too.
It was known as the Union of the Crowns.
Just over a hundred years later, parliaments of England and Scotland passed the Acts of Union. It joined the two separate states into one, the Kingdom of Great Britain. One parliament, one monarch.
1945 saw the first Scottish National Party MP elected to parliament, on a manifesto of breaking Scotland out of the United Kingdom.
Political flyers like these failed to drum up enough support in 1979, when Scotland held a referendum on creating a Scottish parliament.
But in 1997, it passed by a landslide.
Two years later, a Scottish parliament sat for the first time in 272 years.
Already decisions on Scottish education, public health services and the environment are made there. And if the referendum gets a yes vote, Scotland’s future will be decided entirely within its own seat of power.