James I reigned as king of Scotland from April 4, 1406 until February 21, 1437. However, from 1406 to 1424 he was king in name only.

He was born on December 10, 1394, the son of Robert III and Annabella Drummond. He had an eventful childhood. In 1402 his elder brother, David, starved to death in prison at Falkland in Fife. Before the death of his father in 1406 the authorities sent James to France for safety.
On the voyage to France, the English captured the young prince and handed him over to Henry IV of England, who imprisoned him and demanded a ransom. Robert III allegedly died from grief over the capture of James. James's uncle, Robert Stewart, 1st Duke of Albany, who became Regent on the death of Robert III, showed no haste in paying for his nephew's release. Albany secured the release of his own son Murdoch, captured at the same time, but not so with James. So for the next 18 years James remained a prisoner/hostage in England. Henry IV had the young Scots King imprisoned and educated in Windsor Castle and in secure large country houses near London.

After the death of James's uncle in 1420, the Scots finally paid the ransom of £40,000, and in 1424 James returned to Scotland to find a country in chaos. He took his bride with him – he had met and fallen in love with Joan Beaufort, a cousin of King Henry VI of England, while imprisoned. He married her in London in February 2, 1423. They would have eight children, including the future James II of Scotland, and Margaret, wife of Louis XI of France. Scholars believe that during his captivity James wrote ‘The Kingis Quair’, an allegorical romance, one of the earliest major works of Scottish literature.

James was formally crowned King of Scotland at Scone Abbey, Perthshire, on May 2 or 21, 1424. He immediately took strong actions to regain authority and control. In one such action he had the Albany family, who had opposed his actions, executed. The execution of Murdoch, Duke of Albany, and two of Murdoch's sons took place on May 24, 1425 at Castle Hill, Stirling.

James proceeded to rule Scotland with a firm hand, and achieved numerous financial and legal reforms. For instance, for the purpose of trade with other nations, he made Scots coinage exchangeable for foreign currency only within Scottish borders. He also tried to remodel the Parliament of Scotland along English lines. However, in foreign policy, he renewed the Auld Alliance, a Scottish-French (and therefore anti-English) alliance, in 1428.

His actions throughout his reign, though effective, upset many people. During the later years of his reign, they helped to lead to his claim to the throne coming under question.

James I's grandfather, Robert II, had married twice and the awkward circumstances of the first marriage (the one with James's grandmother Elizabeth Mure) led some to dispute its validity. Conflict broke out between the descendants of the first marriage and the unquestionably legitimate descendants of the second marriage over who had the better right to the Scottish throne. Matters came to a head on February 21, 1437, when a group of Scots led by Sir Robert Graham assassinated James at the Friars Preachers Monastery in Perth. He attempted to escape his assailants through a sewer. However, three days previously, he had had the other end of the drain blocked up because of its connection to the tennis court outside, balls habitually got lost in it.

A wave of executions followed in March, 1437, of those who had participated in the plot. The authorities executed (among others) James's uncle, Walter, Earl of Atholl, and Atholl's grandson, Robert, Master of Atholl - both of them descended from Robert II's second marriage).