John Cochrane, 4th Earl of Dundonald

He voted in the election of Scottish representatives on 17 June 1807, but his votes were set aside as he was a minor.^[2]

Lord Dundonald served as a Tory Representative Peer for Scotland from 1713 to 1714. He was a Colonel of the 4th Horse Guards from 1715 to 1719.^[2]

On 4 April 1706, Lord Dundonald was married to Lady Anne Murray (1687–1710) at Cramond. Lady Anne was the second daughter of Charles Murray, 1st Earl of Dunmore and the former Catharine Watts (daughter and heiress of Richard Watts, of Great Munden). Before her death on 30 November 1710 from smallpox, they were the parents of:^[2]

• Lady Anne Cochrane (c. 1706–1724), who married, as his first wife, James Hamilton, 5th Duke of Hamilton, in 1723.^[4]
• William Cochrane, 5th Earl of Dundonald (1708–1725), who died unmarried.^[2]
• Lady Susan Cochrane (d. 1754), who married Charles Lyon, 6th Earl of Strathmore and Kinghorne, in 1725. After his death, she married George Forbes, Master of the Horse, to Prince Charles Edward Stuart, in 1745.^[5]
• Lady Catherine Cochrane (d. 1786), who married, as his second wife, her cousin Alexander Stewart, 6th Earl of Galloway, in 1729.^[6]

After the death of his first wife, he married Mary Somerset, Duchess of Beaufort (1688–c. 1721) on 15 October 1715. Mary, the widow of Henry Somerset, 2nd Duke of Beaufort, was the youngest daughter of Peregrine Osborne, 2nd Duke of Leeds and the former Bridget Hyde (only daughter and heiress of Sir Thomas Hyde, 2nd Baronet, of Aldbury).^[2]

Lord Dundonald died on 5 June 1720 before reaching age 33. He was succeeded in his titles by his only son, William. His widow died in Scotland in c. 1721.^[2]