Mary inherited the kingdom as a six-day-old newborn

Mary was born in Linlithgow Palace, Scotland, on December 8, 1542, to King James V and his French second wife, Mary of Guise. She was reported to have been born prematurely and to have been James's only legitimate child to survive him. Her paternal grandmother, Margaret Tudor, was Henry VIII's older sister, making her the great-niece of King Henry VIII of England. On 14 December, six days after her birth, her father died, either as a result of a psychological breakdown following the Battle of Solway Moss or from drinking contaminated water while on the campaign.

According to a classic story initially told by John Knox, when James learned on his deathbed that his wife had given birth to a daughter, he ruefully remarked, "It cam wi' a lass and it will gang wi' a lass!" In the 14th century, his House of Stuart ascended to the throne of Scotland through the marriage of Marjorie Bruce, daughter of Robert the Bruce, to Walter Stewart, 6th High Steward of Scotland. The crown had arrived at his family via a woman and would leave his family via a woman. This fabled statement was fulfilled decades later, not by Mary, but by her great-great-granddaughter Anne, Queen of Great Britain.

As one of the most interesting facts about Mary Queen of Scots, Mary inherited the kingdom as a six-day-old newborn. Therefore, Scotland was controlled by regents until she reached the age of majority. There were two claims to the regency from the start: one from the Catholic Cardinal Beaton and one from the Protestant Earl of Arran, who was next in line to the throne. Beaton's claim was based on a counterfeit of the king's will, which his opponents dismissed. Arran became regent with the backing of his allies and relatives until 1554 when Mary's mother was able to remove and succeed him.