In 1328 King Edward III of England was forced to agree that Scotland was an independent country and Robert Bruce became the first King of Scotland. Immediately afterward the English decided that they didn’t mean it and while they continually insisted that Scotland was under the rule of England, Scotland ruled itself under their own Monarchy. In 1567 James VI (son of Mary Queen of Scots and of King James Bible fame) was crowed King of Scotland. When Queen Elizabeth of England died in 1603 James also became King James I of England because his great grandmother was the sister of Henry VIII. Despite the union of the crowns of England and Scotland, England decided at that time that it did not want to be a part of a unified country with Scotland. 

(Book – Scotland: The Story of a Nation – Magnus Magnuson)