John Frederick Campbell (born 8th November 1790, died 7th November 1860) was the eldest son of John Campbell of Stackpole Court, Pembrokeshire, first Baron Cawdor. In 1821 John Frederick succeeded to his father's Barony, and in 1816 he married Elizabeth Thynne, daughter of the Marquis of Bath. In 1827 he was created Earl Cawdor of Castlemartin. He was a Fellow of the Royal Society, and Lord Lieutenant of Carmarthen.
The coat-of-arms of Calder, which is given the place of honour in Lord Cawdor's coat, is borne by right of Muriel, heiress of John Calder, or Cawdor, of Nairn. She married Sir John Campbell, son of Archibald, Earl of Argyll, about 1510, and was the ancestress of the present family.
CAPELL, WILLIAM, EARL OF ESSEX
Arms.—Gu., a lion rampant between 3 crosses crosslet fitchée or. Capell.
Coronet.—That of an Earl.
Supporters.—Two lions rampant arg., ducally crowned gu.
Motto.—Fide et fortitudine.
[Basnage. History of the Jews. London, 1708.]