Gilbert Kennedy, 3rd Earl of Cassilis

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Gilbert Kennedy, 3rd Earl of Cassillis

Also Known As: "Gilbert", "3rd Earl of Cassillis"
Birthdate: (43)
Birthplace: Culzean Castle, Maybole, Ayrshire, Scotland
Death: Died in Dieppe, Seine-Maritime, Haute-Normandie, France
Cause of death: Suspected poisoning by the Court of France
Place of Burial: Maybole, Ayrshire, Scotland
Immediate Family:

Son of Gilbert Kennedy, 2nd Earl of Cassillis and Isabel Wallace, Countess of Cassillis
Husband of Margery Sophia Kennedy
Father of Isobel Kennedy, Lady Grymett; Gilbert Kennedy, 4th Earl of Cassilis; Catherine Kennedy; Janet Kennedy, Countess of Orkney; Sir Thomas Kennedy, 1st of Culzean and 3 others
Brother of Quintin Kennedy, Abbot of Crossraguel; Thomas Kennedy; David Kennedy of Culzean; Archibald Kennedy; James Kennedy and 7 others

Occupation: Third Earl of Cassillis
Managed by: Private User
Last Updated:

About Gilbert Kennedy, 3rd Earl of Cassilis,_3rd_Earl_of_Cassilis

Gilbert Kennedy, 3rd Earl of Cassilis (/ˈkæslz/ KASS-lz) (1515 – 28 November 1558) was Scottish landowner, soldier, politician and judge. He served as Treasurer of Scotland.

The son of Gilbert Kennedy, 2nd Earl of Cassilis, he succeeded to the titles of 5th Lord Kennedy and 3rd Earl of Cassillis in August 1527. On 6 February 1540/41 he had a charter of the Fief of Cassilis.

Gilbert Kennedy was taken prisoner by Thomas Dacre and Sir William Musgrave in the Battle of Solway Moss in 1542.

Being committed to the custody of Thomas Cranmer, Archbishop of Canterbury, was, by the instructions of that venerable martyr, induced to embrace the reformed religion. He became a Protestant, and went over to the English Party. He was released in February 1545, and held the office of Treasurer of Scotland in 1554, of Extraordinary Lord of Session between 1546 and 1558. Gilbert Kennedy fought in the Battle of Pinkie Cleugh on 10 September 1547.

In 1558 he was present, as one of the eight Commissioners appointed by the Scottish Parliament, at the marriage of Mary, Queen of Scots, to the Dauphin of France, to whom the Scottish deputies unanimously refused the Crown matrimonial. The Court of France appeared deeply mortified by this disappointment, and the Earl of Cassilis, with two others of the Commissioners, dying in one night, on 28 November 1558, at Dieppe, a report was raised that they had been poisoned, which was further countenanced by the death of a fourth Commissioner, Lord Fleming, at Paris, on 16 December 1558.

Henry II of France had appointed Gilbert as Gentleman in Ordinary of his Chamber on 4 May 1558, and this honour was transferred to his heir, Gilbert, 4th Earl of Cassilis on 10 February 1559.


The Earl married Margaret Kennedy in 1540 and they had five children.

Katherine Kennedy

Gilbert Kennedy, 4th Earl of Cassilis (c. 1541–1576)

Sir Thomas Kennedy, Master of Cassilis (b. between 1543–1558, d. 1602)

Jane or Jean Kennedy, (bef. 1558–c.1598), married Robert Stewart, 1st Earl of Orkney

Lady Isobel Kennedy b. 24 July 1542 d. 12 Jan 1598 and had descendants


Gilbert Kennedy, 3rd Earl of Cassillis, was born between 1515 and died 28 November 1558.

Gilbert, 3rd Earl of Cassillis, was a famous Scottish statesman and he was appointed Lord High Treasurer in 1554. He was one of the Commissioners who went to France to arrange the marriage of Mary, Queen of Scots, with the Dauphin, and, because he refused to agree that the Scottish crown should go to the French heir, he was poisoned at Dieppe and his body was also brought back for burial in the "Auld College".

Parents: son of Gilbert Kennedy, 2nd Earl of Cassillis and Lady Isabel Campbell.

Pedigree: (Gilbert12, David11, John10, Gilbert9, James8, Gilbert7, John6, Gilbert5de Carrick, Gilbert4, Roland3, Nicol,2, Duncan1)


  1. Margaret Kennedy, daughter of Alexander Kennedy of Bargany.

Children include:

  1. Lady Janet Kennedy+1 d. 1598
  2. Gilbert, fourth Earl of Cassillis ancestor of the fifth, sixth, seventh and eighth Earls of Cassillis.
  3. Hon. Sir Thomas of Culzean, Master of Cassillis, b. bt 1543 - 1558, d. 11 May 1602 m. Elizabeth McGill.
  4. Lady Jean; m. Robert (--?--) Earl of Orkney
  5. Lady Catherine; m. Sir Patrick Vaus.


He succeeded as 3rd Earl of Cassillis. William Kennedy Abbot of Crossraguel was his guardian for eleven years. He was at the University of St. Andrew's in 1527, afterwards completed his education om Paris, remaining there until 1537; of excellent disposition and promising talents. He had many charters; when taken prisoner at rout of Solway Moss by the English he was committed to Archbishop Cranmer, 1542, because an Anglican. Henry VIII loaded him with gifts. He was high Treasurer of Scotland, Chief Commander in the Army which attacked Berwick and invaded England 1557. Sent to France to negotiate Queen Mary's marriage with the Dauphin but met mysterious death at Dieppe in 1558; buried at Maybole.


BIOGRAPHY: Gilbert KENNEDY, Earl of Cassillis, born 1515; educated at the University of St. Andrews and at Paris. On Feb. 6, 1540/1, he had a charter of the Fief of Cassillis, to himself and the male heirs of his body. He wastaken prisoner by the English at Solway Moss, November 24, 1542, but was allowed to return to Scotland early in 1543, and, failing to surrender himself, his three sureties and kinsmen, being in great peril of their lives, wrote December 11, 1544, imploring him to do so. He was finally discharged in February, 1545. He shared in the Scottish defeat at Pinkie in September, 1547. He became a Protestant and went over to the English party. He was HIGH TREASURER of Scotland, 1554, until his death. He was one of the 8 members chosen to represent his country at the marriage of Mary, Queen of Scots with the Dauphin of France, which was celebrated in Paris April 24, 1558.

BIOGRAPHY: The sudden death of no less than 4 of these( who had opposed the French views as to the settlement of the Scottish Crown), led to a strong suspicion of poison. He died at Dieppe, November 28, 1558, and was buried with his ancestors at Maybole. He married in 1540, Margery Sophia Kennedy, widow of William Wallace of Craige. She was the daughter of Alexander Kennedy or Bargeny. His widow's will was proved at Edinburgh, January 12, 1596/7.

SOURCES:FamilySearch, Family Group, Family ID= 1833920.

◦Marriage: Gilbert KENNEDY md Margery or Margaret Sophia KENNEDY, 1540.

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Gilbert Kennedy, 3rd Earl of Cassilis's Timeline

Culzean Castle, Maybole, Ayrshire, Scotland
Age 20
Age 26
Maybole, Ayrshire , Scotland
Age 27
Age 27
Kirkmichael, Ayrshire, Scotland
Age 30
Maybole, Ayrshire , Scotland
November 28, 1558
Age 43
Dieppe, Seine-Maritime, Haute-Normandie, France