The Scots sought help from the French, to defeat the English.
On 16 June 1548 thousands of French troops arrived at the port of Leith in Edinburgh and attacked Haddington with artillery.
The price of this French support was that on 7 July, the Scots and French signed the Treaty of Haddington. This promised that Mary Stuart would marry the Dauphin Francis - the heir to the French throne.
The Earl of Arran then persuaded the Scottish Parliament to favour a French marriage for the Queen. He was rewarded for this with a French Duchy (a piece of territory) - he became the Duke of Châtelherault.
The French fleet, which had carried the soldiers, sailed to Dumbarton. It subsequently departed to France with the young Mary and her four young attendants; Mary Seton, Mary Beaton, Mary Livingstone and Mary Fleming. These attendants were more commonly known as 'The Four Marys'.
In France, Mary was brought up in the Catholic faith. In April 1558 Mary married the Dauphin Francis. She was only 16 years old at the time of her marriage. A year later the King of France died. Francis and Mary now became King and Queen of France.
Mary also became used to French customs and language before returning to Scotland in 1561. Meanwhile, in Scotland, Mary’s mother (Mary of Guise) had become Regent in 1554.