Sir Robert Kerr, or Carr, was the fourth son of Sir Thomas Kerr, of Ferniehurst, and his second wife, Janet, sister of Sir Walter Scott, of Buccleuch. He accompanied James I to England as a Page of Honour and became a great favourite of the King. He was installed a Knight of the Garter in 1611 at which time he was given an honourable augmentation to his arms in the form of a lion of England in the dexter chief, and was granted the quartering at the request of the King. He was created Viscount Rochester 15 March 1611 and Earl of Somerset 3 November 1613. He married the Countess of Essex, who had obtained an annulment of her marriage 26 December 1613, and held a number of offices of state and in the King's Household. In the autumn of 1615 information was laid that Somerset and his wife were implicated in the murder of Sir Thomas Overbury and they spent six years in the Tower of London, but were subsequently pardoned, though not received back into favour.