The 5th laird was succeeded as 6th laird by his son, Sir James Hamilton, who was created a Lord of Parliament as Lord Hamilton on 3 July 1445.
In early 1474, he married Princess Mary, Countess of Arran, daughter of King James II and widow of Thomas Boyd, 1st Earl of Arran.
He was succeeded by his only legitimate son, James, 2nd Lord Hamilton.
In 1490, then aged 15, he married the 13-year-old Elizabeth, Lady Hay, daughter of Alexander Home, 2nd Lord Home and widow of Sir Thomas Hay, Master of Yester, son and heir of John Hay, 1st Lord Hay of Yester.
However, it was later discovered that Sir Thomas Hay was still alive and the marriage was annulled.
The 2nd Lord married secondly Janet, Lady Livingstone, daughter of Sir David Beaton of Creich and widow of Sir Robert Livingstone of Easter Wemyss and Drumry.
He became a Privy Counsellor to King James IV, and helped to arrange his marriage to Princess Margaret, daughter of King Henry VII of England.
As a reward he was created Earl of Arran on 8 August 1503.
He was succeeded by his elder son from his second marriage, James, 2nd Earl of Arran.
He was Regent of Scotland between 1542 and 1554, and guardian of the young Mary, Queen of Scots.
He was created Duc de Châtellerault in the Peerage of France in 1548 for his part in arranging the marriage of Queen Mary to Francis, Dauphin of France.
This French Dukedom was forfeit when he switched allegiances in 1559.
Emperor Napoleon III "confirmed" this title for the 12th Duke of Hamilton in the 19th century, but although the 12th Duke was heir male of the 2nd Earl, the legal effect of this "confirmation" is doubtful.

The 2nd Earl was succeeded by his eldest son, James, 3rd Earl of Arran, who had been proposed as a husband to Queen Elizabeth I of England in 1561.
In 1562 he was declared insane, and in 1581 he resigned the Earldom to James Stewart of Bothwellhaugh.
However, in 1586 his resignation was ruled by the Court of Session to be the act of a madman and his honours were restored.
The 5th laird was succeeded as 6th laird by his son, Sir James Hamilton, who was created a Lord of Parliament as Lord Hamilton on 3 July 1445. In early 1474, he married Princess Mary, Countess of Arran, daughter of King James II and widow of Thomas Boyd, 1st Earl of Arran. He was succeeded by his only legitimate son, James, 2nd Lord Hamilton. In 1490, then aged 15, he married the 13-year-old Elizabeth, Lady Hay, daughter of Alexander Home, 2nd Lord Home and widow of Sir Thomas Hay, Master of Yester, son and heir of John Hay, 1st Lord Hay of Yester. However, it was later discovered that Sir Thomas Hay was still alive and the marriage was annulled. The 2nd Lord married secondly Janet, Lady Livingstone, daughter of Sir David Beaton of Creich and widow of Sir Robert Livingstone of Easter Wemyss and Drumry. He became a Privy Counsellor to King James IV, and helped to arrange his marriage to Princess Margaret, daughter of King Henry VII of England. As a reward he was created Earl of Arran on 8 August 1503. He was succeeded by his elder son from his second marriage, James, 2nd Earl of Arran. He was Regent of Scotland between 1542 and 1554, and guardian of the young Mary, Queen of Scots. He was created Duc de Châtellerault in the Peerage of France in 1548 for his part in arranging the marriage of Queen Mary to Francis, Dauphin of France. This French Dukedom was forfeit when he switched allegiances in 1559. Emperor Napoleon III "confirmed" this title for the 12th Duke of Hamilton in the 19th century, but although the 12th Duke was heir male of the 2nd Earl, the legal effect of this "confirmation" is doubtful.
The 2nd Earl was succeeded by his eldest son, James, 3rd Earl of Arran, who had been proposed as a husband to Queen Elizabeth I of England in 1561. In 1562 he was declared insane, and in 1581 he resigned the Earldom to James Stewart of Bothwellhaugh. However, in 1586 his resignation was ruled by the Court of Session to be the act of a madman and his honours were restored.
Duke of Hamilton