James Hamilton, Duke of Châtellerault

James Hamilton was the eldest legitimate son of James Hamilton, 1st Earl of Arran by his second wife, Janet Bethune. His paternal grandmother, Mary, was the daughter of King James II. On the death of John Stewart, Duke of Albany, in 1536, he became next in line to the throne after the King's descendants.

The children of the immediate royal family proved to be short-lived, so on the death of James V of Scotland on 14 December 1542 at only 30, the Earl of Arran stood next in line to the Scottish throne after the king's six-day-old newborn baby daughter Mary, Queen of Scots, for whom Arran was appointed Governor and Protector of Scotland. In 1543, supporters of Matthew Stewart, 4th Earl of Lennox, challenged Arran's claim and legitimacy by suggesting that his father's divorce and second marriage were invalid.

Initially a Protestant and a member of the pro-English party, in 1543 he was involved in negotiating the marriage of the Queen of Scots to the infant Prince of Wales (the future Edward VI of England). Cardinal Beaton, who favoured the Auld Alliance, was imprisoned at Dalkeith Palace and then Blackness Castle. Henry VIII of England doubted Arran's commitment to English policy and wanted him deposed. On 18 March 1543, Sir George Douglas of Pittendreich, brother of the Earl of Angus, told the English ambassador, Ralph Sadler, that;

"if there be any motion now to take the Governor from his state, and to bring the government of this realm to the king of England, I assure you it is impossible to be done at this time. For, there is not so little a boy but that he will hurl stones against it, and the wives will handle their distaffs, and the commons universally will rather die in it, yea, and many noblemen and all the clergy be fully against it."

On 3 September 1543 there was panic in Edinburgh when it became known that Arran had quietly left town. Although he had said that he was visiting his pregnant wife at Blackness Castle, the pro-English party guessed he would try to meet Cardinal Beaton. The Governor and the Cardinal were reconciled at Callendar House. Shortly after, Arran became a Catholic and joined the pro-French faction, consenting to the marriage of the Queen to the French Dauphin, later Francis II of France, and earning the Duchy of Châtellerault in the process. This led to the seven-year war with England now called the Rough Wooing which was declared on 20 December 1543. The declaration of war was brought by Henry Ray to give to the Parliament of Scotland. Arran replied that the parliament was dissolved, and so he thought it expedient not to answer Henry VIII on the points raised at the time. In September 1547 Arran assembled a large Scottish army to resist an English invasion led by Edward Seymour, Duke of Somerset but was defeated at the Battle of Pinkie Cleugh. He nevertheless held onto the regency and continued to lead forces against the occupying troops. In 1548 the Queen of Scots went to live in the French court. For his work on negotiating her marriage, Hamilton was created Duke of Châtellerault, and made a knight of the Order of Saint Michael.

In 1554, Arran surrendered the regency to Mary of Guise, Queen Mary's mother, and was appointed her lieutenant in Scotland. He gave up the Regency on the condition that he would be the Queen's heir, if she died childless. But the Scottish succession had been secretly promised to France.

In the first months of the Scottish Reformation Hamilton continued to support Mary of Guise. He faced a Protestant army with the French commander at Cupar Muir in June 1559. He changed his allegiance in August 1559, joining the Protestant Lords of the Congregation to oppose the regency of Mary of Guise, and lost his French dukedom as a result. After the death of Guise, Hamilton persuaded the Parliament of Scotland to back a plan to marry his son James to Elizabeth I of England, and then after the death of Francis II of France in 1560 he attempted, without success, to arrange for James to marry the young widowed Queen Mary.

After Mary married Lord Darnley in 1565 he withdrew to his estates in France. In 1569, he returned to Scotland and was imprisoned until, in 1573, he agreed to recognise Mary's infant James as King of Scotland.

A building from his heyday as Regent survives at Kinneil in West Lothian, his Eastern residence, including carvings and paintings of his heraldry with the collar of Saint Michael.

Arms of the Duke and Margaret Hamilton, Kinneil House (Historic Scotland)

Hamilton married in 1532, to the Lady Margaret Douglas, daughter of James Douglas, 3rd Earl of Morton, and Catherine Stewart, herself a natural daughter of James IV. His older half-brother James Hamilton of Finnart paid Morton 4000 marks as part of the marriage settlement. They had the following issue:

• James Hamilton, 3rd Earl of Arran
• Lady Anne Hamilton – married George Gordon, 5th Earl of Huntly
• Lady Jean Hamilton – married Hugh Montgomerie, 3rd Earl of Eglinton
• Lady Barbara Hamilton – married first Alexander Gordon, Lord Gordon, then James Fleming, 4th Lord Fleming
• John Hamilton, 1st Marquess of Hamilton – married Margaret, daughter of John Lyon, 7th Lord Glamis as her second husband
• Lady Margaret Hamilton – married Sir Alexander Pethein (Peden)
• Gawain Hamilton – died in infancy
• Lady Elizabeth – married George Hamilton
• David Hamilton – had three children in 1575.
• Claud Hamilton, 1st Lord Paisley – married Margaret, daughter of George Seton, 7th Lord Seton

The marriage was arranged by Hamilton's elder half-brother and guardian James Hamilton of Finnart. Margaret Douglas was given the house and lands of Kinneil House for her lifetime if her husband died before her. In 1544 Regent Arran attempted unsuccessfully to get a divorce. Recently Amy Blakeway has argued that attempted divorce might have been related to Margaret's poor mental health, for which there is later evidence.