Joan Beaufort lived from about 1404 to 15 July 1445. Of English descent, she married James I of Scotland and was the mother of James II. The wider picture in Scotland at the time is set out in our Historical Timeline.
From the age of 12 in 1406, James I of Scotland spent 18 years of his life as a prisoner/guest/hostage in England. While there he met and fell in love with Joan Beaufort, the daughter of John Beaufort, 1st Earl of Somerset and Margaret Holland. It is said that while in captivity, James was inspired by his love for Joan to write The Kingis Quair an allegorical romantic poem which was to become one of the first major pieces of Scottish literature. The Beauforts were closely related to the English monarchs, and one of Joan's cousins later became King Henry VI. Joan was named after her aunt, Joan Beaufort, Countess of Westmorland.
Joan accompanied James I when he eventually returned to Scotland in 1424. They had eight children together. Six of the children were girls, three of whom went on to marry the King of France, the Archduke of Austria and the Duke of Brittany. They also had twin boys, one of who died in infancy. The other was to become James II.
James I set about transforming his kingdom with a vigor that made him many enemies. To make things worse, doubts about the validity of the first marriage of James' grandfather, Robert II, raised questions about James' own right to the crown of Scotland. James found himself facing challenge from descendents of his grandfather's (unquestionably legal) second marriage.
On 20 February 1437, plotters supporting the claim to the throne of Walter, Earl of Atholl, a son of Robert II's second marriage, broke into the Dominican Friary in Perth where James I was staying with Queen Joan. James tried to escape by climbing down a sewer that exited onto the tennis court where he had spent many of his days. Ironically he had instructed that the outlet be blocked the previous day to prevent tennis balls being lost. James was cornered in the sewer and killed by Sir Robert Graham.
Queen Joan, though injured, escaped, and took their 6 year old son James - now James II - for safety to Stirling Castle. She then took immediate and dramatic steps to safeguard her son's hold on the throne by wiping out the side of Robert II's family responsible for murdering James I, with a savagery that was remarkable even for the times.
Joan was Regent of Scotland for her son until her marriage in 1439 to James Stewart, the Black Knight of Lorn. Thereafter she was sidelined from matters of state. She had three sons by her second marriage, who went on to become the 1st Earl of Atholl, the 1st Earl of Buchan, and the Bishop of Moray. She died in 1445.