When Elizabeth died in 1603, the crown was offered to James VI, King of Scots. Since he was the first James on the English throne he was known as James VI and I. The Reformation had taken an entirely different trajectory in Scotland than it did in England. It may be helpful here to compare what had happened in Scotland in the preceding years, and what mentality James brought down to England.
“Cuius regio, eius religio” was true of England and many other countries, but the monarchy in Scotland was in a weak state after the death of James V in 1542. His daughter and only heir, Mary, had been born only six days before, so a succession of regents covered the next 18 years. Mary’s mother, Mary of Guise, sent her daughter at a tender age to her family in France. In 1558, aged 16, she married the Dauphin, heir to the French throne, and when he became King the next year, she became Queen Consort of France. However, her husband died a year later in December 1560. Mary set about to come back to Scotland to claim her Scottish throne, aged still 18 years of age. By the time she returned in August 1561, events had run ahead of her.