The son of Sir Thomas Hamilton of Priestield, a judge of the Court of Session as Lord Prestonfield, by his first wife Elizabeth, daughter of James Heriot of Trabroun, Haddingtonshire.

Widely regarded as an able administrator, Hamilton was entrusted with a large share in the government of Scotland when James moved to London in 1603.

[4] Anne of Denmark, according to Hamilton, told Lady Paisley and her physician Martin Schöner that she had taken "balm water".

[5] The Earl of Montrose, Lord Chancellor of Scotland, made efforts to calm the controversy and help set Anne of Denmark on her way to England in June.

[9] In 1612 he was appointed Lord Clerk Register to the Privy Council to succeed John Skene.

After the death of James VI, the earl resigned his offices, but served Charles I as Keeper of the Privy Seal of Scotland.

Anne Ker, the wife of John Elphinstone, 2nd Lord Balmerino, described how her sister, Julian Ker, Lady Binning, presented a petition on behalf of Robert Carr, 1st Earl of Somerset to the King at Holyrood Palace.

The petitioners, Somerset's Scottish allies, including Hamilton, kneeled in the privy gallery while Lady Binning gave the petition to the king.

In 1624, under the title of Thomas Hamilton, Earl of Melrose, he purchased Balgone House south-east of North Berwick.

[12] Before her death on 31 May 1609, they were the parents of: His third marriage was to Julian, Lady Hume (née Ker) on 3 September 1613.

This list included items which he had "brought home", meaning that he had purchased them in London or imported them.