James I (late July 1394 – 21 February 1437) was King of Scots from 1406 until his assassination in 1437. The youngest of three sons, he was born in Dunfermline Abbey to King Robert III and Annabella Drummond. His eldest brother David, Duke of Rothesay, died under suspicious circumstances while detained by his uncle, Robert, Duke of Albany. James's other brother, Robert, died young. Concerns for James's safety deepened in the winter of 1405–1406 prompting plans to send him to France. In February 1406, James took refuge in the castle of the Bass Rock in the Firth of Forth after his escort was attacked by supporters of Archibald, 4th Earl of Douglas. He remained there until mid-March when he boarded a vessel bound for France. On 22 March, an English vessel captured the ship and delivered James to Henry IV of England. The ailing Robert III died on 4 April and the 11-year-old James, now the uncrowned King of Scotland, would remain in captivity for eighteen years.

James was educated well during his imprisonment in England, where he was often kept in the Tower of London, Windsor Castle, and other English castles. He was generally well-treated and developed respect for English forms of governance. James joined Henry V of England in his military campaigns in France between 1420 and 1421. His cousin, Murdoch Stewart (Albany's son), an English prisoner since 1402, was traded for Henry Percy, 2nd Earl of Northumberland, in 1416. However, Albany refused to negotiate James's release. James married Joan Beaufort, daughter of the Earl of Somerset, in February 1424, shortly before his release in April. His return to Scottish affairs was not altogether popular due to his service to Henry V in France, sometimes against Scottish forces. Noble families faced increased taxes to fund the ransom payments, and to provide family hostages as security. James, who excelled in sports, literature, and music, aimed to impose law and order on his subjects but sometimes he applied such order selectively.

To secure his position in the Scottish court, James launched pre-emptive attacks on some of his nobles beginning in 1425 with his close kinsmen, the Albany Stewarts. This led to the execution of Duke Murdoch and his sons. In 1427 James summoned the Highland clans to a sitting of parliament in Inverness, and they came in great numbers. There, James unscrupulously had some murdered and imprisoned others, including Alexander, Lord of the Isles, along with his mother, Mariota, Countess of Ross. This betrayal effectively destroyed any peace he might have had with them.

Archibald, 5th Earl of Douglas, was arrested in 1431, followed by George, Earl of March, in 1434. The fate of the hostages in England was ignored by Scotland's ruling elite and the repayment money was diverted into the construction of Linlithgow Palace and other schemes. In August 1436, James's siege of Roxburgh Castle failed, and he subsequently faced an ineffective attempt by Sir Robert Graham to arrest him at a general council. On the night of 20/21 February 1437, James was assassinated in Perth during a failed coup by his uncle Walter Stewart, Earl of Atholl. Queen Joan, though wounded, escaped the attackers and reached Edinburgh Castle to be reunited with her son, the new King James II.

James was probably born in late July 1394 at Dunfermline Abbey, 27 years after the marriage of his parents, Robert III and Annabella Drummond. It was also at Dunfermline under his mother's care that James would have spent most of his early childhood. He was seven years old when his mother died in 1401, and a year later his elder brother David, Duke of Rothesay, was probably murdered by their uncle Robert Stewart, Duke of Albany, after being held at Albany's Falkland Castle. James, now heir to the throne, was the only barrier to the Albany Stewarts' royal ambitions. In 1402 Albany and his close ally Archibald, 4th Earl of Douglas, were absolved of Rothesay's death allowing Albany's reappointment as King's Lieutenant.

Albany rewarded Douglas for his support by allowing him to resume hostilities with England but their fortunes suffered a serious reversal in September 1402 when English troops defeated their large army at the Battle of Homildon Hill. Numerous Scottish nobles and their followers were captured, including Douglas himself, Albany's son Murdoch, and the earls of Moray, Angus and Orkney. 1402 also saw the death of Rothesay, that of Alexander Leslie, Earl of Ross and Malcolm Drummond, Lord of Mar. This power vacuum was inevitably filled by individuals who were not involved in national politics. In the years between 1402 and 1406, the northern earldoms of Ross, Moray and Mar were without adult leadership and with Murdoch Stewart, the justiciar for the territory north of the Forth in an English prison, Albany found himself reluctantly having to ally with his brother the Earl of Buchan, and Buchan's son, Alexander, to counter the ambitions of the Lord of the Isles. Douglas's absence allowed King Robert's allies Henry Sinclair, Earl of Orkney, and Sir David Fleming of Biggar to become the main political force in the Lothians and Scottish Marches.

In December 1404 the king granted the royal Stewart lands in the west (Ayrshire and around the Firth of Clyde), to James in regality, protecting them from outside interference and providing the prince with a territorial centre should the need arise. Yet in 1405, James was under the protection and tutelage of Bishop Henry Wardlaw of St Andrews on the country's east coast. The animosity of the Douglas affinity was intensifying due to Orkney's and Fleming's expanding influence in border politics and relations with England. Although a decision to send the young prince to France and out of Albany's reach was taken in the winter of 1405–1406, James's departure from Scotland was unplanned. In February 1406 Bishop Wardlaw released James to Orkney and Fleming who, with their large force of Lothian adherents, proceeded into hostile Douglas east Lothian. James's custodians may have been displaying royal approval to further their interests in Douglas country. This provoked a fierce response from James Douglas of Balvenie and his supporters who, at a place called Long Hermiston Muir, engaged with and killed Fleming while Orkney and James escaped to the comparative safety of the Bass Rock islet in the Firth of Forth. They endured more than a month there before boarding the France-bound Maryenknyght, a ship from Danzig. On 22 March 1406, the ship was captured by an English vessel that was under the partial ownership of English politician Hugh Fenn; the vessel's crew delivered James to Henry IV of England, who kept him as a hostage. Robert III was at Rothesay Castle when he learned of his son's capture and he died soon after, on 4 April 1406, and was buried in the Stewart foundation abbey of Paisley.

James, now the uncrowned King of Scots, began what proved to be his 18-year period as a hostage while, simultaneously, Albany transitioned from lieutenant to governor. Albany took James's lands under his control, depriving the king of income and any of the regalia of his position, and James was referred to in records as 'the son of the late king'. The king had a small household of Scots that included Henry Sinclair, Earl of Orkney, Alexander Seaton, the nephew of Sir David Fleming, and Orkney's brother John Sinclair, following the earl's return to Scotland. In time, James's household — now paid for by the English — changed from high-ranking individuals to less notable men. Henry IV treated the young James well, providing him with a good education.