James Hamilton, 1st Earl of Abercorn PC (S) (1575–1618), was a Scottish diplomat for James VI and an undertaker (a term for a British colonist) in the Plantation of Ulster in the north of Ireland.
James was born on 12 August 1575, probably at Paisley, Scotland, the eldest son of Claud Hamilton and his wife Margaret Seton. His father was a younger brother of the 3rd Earl of Arran, and would be created Lord Paisley on 24 July 1587. His paternal grandfather was the 2nd Earl of Arran in the Peerage of Scotland and the Duke of Châtellerault in the Kingdom of France. His father's family descended from Walter FitzGilbert, the founder of the House of Hamilton, who had received the barony of Cadzow from Robert the Bruce.
James's mother was a daughter of George Seton, 7th Lord Seton. His parents had married in 1574 at Niddry Castle, West Lothian, Scotland. Both sides of the family were Scottish, Catholic, and supporters of Mary, Queen of Scots. His father and his father-in-law had both fought for her at Langside in 1568.
As eldest son he was given the courtesy title of Master of Paisley after the Scottish habit. George had four brothers and one sister, who are listed in his father's article.
Shortly before or in 1592, Master Paisley married Marion, daughter of Thomas Boyd, 6th Lord Boyd. Marion was a prominent Roman Catholic and would in 1628 be excommunicated by the synod of the Church of Scotland in Glasgow after his death.
James and Marion had nine children, five boys:
James (c. 1603 – c. 1670), succeeded as the 2nd Earl of Abercorn
Claud (died 1638), established himself in Ireland
William (died 1681), was created Baronet Hamilton of Westport and represented Henrietta Maria, Charles I's widow, at the pope
George (c. 1608 – 1679), was created Baronet Hamilton of Donalong
Alexander (died before 4 May 1669), founded the German branch of the family
Anne (1592–1620), married Hugh Sempill, 5th Lord Sempill in 1611
Margaret (died 1642), married Sir William Cunninghame of Caprington
Lucy (born before 1618), for whom a marriage was arranged with Randal MacDonnell, 1st Marquess of Antrim, but the wedding never took place
In 1597, the Master of Paisley sat for Linlithgow in the Parliament of Scotland. He was also made a Gentleman of the Bedchamber and a member of the Privy Council to James VI of Scotland. In 1600, the King created him hereditary Sheriff of Linlithgow.
On 2 May 1602, the Master of Paisley carried the basin at the baptism of Robert Stuart, Duke of Kintyre and Lorne at Dunfermline Abbey.
On 24 March 1603, at the Union of the Crowns James VI also became King of England and reigned on both kingdoms in personal union. On 5 April 1603, the Master of Paisley was created Lord Abercorn, of Linlithgowshire. This made him the first of the long line of earls, then marquesses, and finally dukes of Abercorn.
His wife was a close friend of Anne of Denmark. In May 1603 Anne of Denmark came to Stirling Castle hoping to collect her son Prince Henry, who was in the keeping of the Earl of Mar. Anne fainted at dinner and when Jean Drummond and Marion Boyd, Mistress of Paisley, carried her to bed she had a miscarriage. The lawyer Thomas Haddington wrote an account of these events, and said the queen had told her physician Martin Schöner and the Mistress of Paisley that she had taken "some balm water that hastened her abort".