Sir Gilbert Kennedy was born circa 1368 in Scotland, United Kingdom to John Kennedy (-c1385) and Mary de Carrick (-c1385) and died circa 1440 Scotland, United Kingdom of unspecified causes. He married Agnes Maxwell (-aft1408) in Scotland.
"Gilbert Kennedy of Dunure ... is styled "filius primogenitus" in a charter, dated 27th January 1384-5, by Malcolm Fleming of Biggar. He was one of the hostages for David II in 1358. 'In 1364-5, he acquired from his father the lands of Strogilton of Poulton, and two Broughtons of Lethydale; and in 1370, during his father's life, he acquired from Thomas Fleming, grandson of Malcolm Earl of Wigtoun, the town of Kirkintilloch. In 1384 he got a charter from Malcolm Fleming of Biggar, confirming a charter by his father John Kennedy, of the forty shilling land of Kirkintilloch in favour of Sir Gilbert Kennedy, his eldest son, and of Agnes Maxwell, wife of the said Sir Gilbert, and the longest liver of them, and the heirs male of (Sir Gilbert's) body, to be lawfully procreated; whom failing, to John Kennedy, brother-germain of the said Gilbert, and to the heirs-male of his body to be lawfully procreated; whom failing, Roland Kennedy, brother germain of the said Gilbert and John, and the heirs-male of his body to be lawfully procreated; whom all failing, the heirs whomsoever of the said John Kennedy of Dunure.
This charter is of importance in a family point of view. These three children, Gilbert, John and Roland were not, it will be observed, sons of Sir Gilbert by his wife Agnes Maxwell, but by a previous marriage or otherwise. Nisbet's Heraldry and the Peerages state, but without authority, that Sir Gilbert was first married to Marion, daughter of Sir James Sandilands of Calder, by whom he is said, in Nisbet, to have had two sons, Gilbert and Thomas. In Wood's Peerage the marriage is stated, but the children are differently arranged. In the "Historical Account" the editor says 'there is no evidence in Lord Ailsa's charter-chest of the first marriage; the only wife of Sir Gilbert Kennedy who is mentioned in any of the titles is Agnes Maxwell, and she is called in various charters, particularly those in 1400 and 1401, the mother of all his children, except Gilbert, John and Roland; and in the charter of 1384, of Kirkintilloch, in which Gilbert is called the oldest son (primogenitus), and John and Roland brothers germain of Gilbert, they are only called failing heirs-male of Sir Gilbert's body to be lawfully procreated. It would therefore appear that they were not legitimate. By our old practice, the word germain does not necessarily infer legitimacy, but only that the children were born of the same mother'.
Agnes Maxwell, the wife of Sir Gilbert Kennedy, was the daughter of Sir John Maxwell of Pollock by his wife, Isabel Lindsay, daughter of Sir James Lindsay of Crawford, by the Princess Egidia, sister of Robert II., not of Sir Robert Maxwell of Calderwood, second son of Sir John as stated in the Peerages. The eldest son of Sir Gilbert Kennedy and Agnes Maxwell was James, who married the Princess Mary, daughter of Robert III. In 1392 Sir Gilbert Kennedy gave an obligation, dated 16th September, to James Kennedy his son, obligating himself not to revoke the grant made by him to the said James Kennedy, and the heirs-male of his body; whom failing, the heirs whatsoever procreate between the said Sir Gilbert Kennedy and Agnes Maxwell, his wife (mother of the said James Kennedy) of the Dominical lands of Kirkintulloch, and lands of Sherreve, Bar, Gartchewar, and Badcall, lying in the barony of Lenzie and county of Dumbarton. On 2d November 1400 he got a charter from David Earl of Carrick, eldest son of Robert III., of the lands of Dunure, Girvan, and Glenap, in favour of himself and Agnes Maxwell, his wife, in liferent, and after their decease, of James Kennedy, their son, and the heirs-male of his body; whom failing, Alexander Kennedy, his brother, and the heirs-male of his body; whom failing, Hugh Kennedy, his brother, and the heirs-male of his body; whom failing, John Kennedy, son of the said Gilbert and Agnes, and brother of the said James, and the heirs-male of his body; whom failing, Thomas Kennedy, their brother, and the heirs-male of his body; whom failing, the nearest heirs whatsoever of the said Sir Gilbert Kennedy, their father. He took a charter in the same terms, in 1404, of the lands of Cassillis and Guletry and two Kilmorce, but in this charter each of the younger sons are called brother of James. These charters were all obtained before the marriage of James with the Princess Mary. This event took place in 1405; upon which occasion Sir Gilbert resigned in favour, and the heirs-male of his body; whom failing his other younger children, in the order above-mentioned, the barony of Dalrymplem and at the same time he resigned, in favor of his son James, under the reservation of his own liferent, the chieftainship and office of bailie of Carrick. After the death of James, who was killed by his brother Gilbert, Sir Gilbert entered into an indenture with the Duke of Albany, governor of the kingdom, dated 8th November 1408, by which he obliged himself to make a taillie of his estates in favour of himself and Agnes Maxwell, his wife, in liferent, and the heirs-male of his son James nominatim, and their heirs-male, in the order above mentioned. These sons are in this deed all called brothers of Alexander, who is called son of Agnes Maxwell.
In 1386 Sir Gilbert Kennedy granted a bond of obligation to the nunnery of North Berwick as to the church of Mayhole. It has the remains of his seal attached to it, displaying a chevron between three cross crosslets, with a label of three points on the shield, and a lion for supporter on the left-the rest way.
With regard to the elder branch of Sir Gilbert's family - Gilbert, John and Roland - there seems to be some uncertainty in reference to their history. Gilbert is said to have died abroad, whither he fled after the slaughter of his brother James, leaving no issue. This is proved by an infeftment, dated 17th April 1466, against Robert Lord Fleming. John, is believed to have been the ancestor of the first family of Kennedy of Coif, who soon became extinct; and from a curious obligation discovered among Lord Ailsa's titles, it is more than probably that Roland was proprietor of Leffnol. The obligation is dated 18th October, 1464, and to the effect that Gilbert Kennedy, son and heir of Roland Kennedy of Leffnol, shall not disturb Gilbert Kenenndy of Dunure, his master, in his lands and offices specified, under penalty of 6000 pounds Scots.
Sir Gilbert Kennedy, died about 1440..." --History of the County of Ayr: With a Genealogical Account of the Families of Ayrshire, Volume 2 by James Paterson
Siblings
| Name | Birth | Death | Joined with |
| Gilbert Kennedy (c1368-c1440) | 1368 Scotland, United Kingdom | 1440 Scotland, United Kingdom | Agnes Maxwell (-aft1408) |
Children
| Name | Birth | Death | Joined with |
| Gilbert Kennedy | |||
| John Kennedy (-) | |||
| Roland Kennedy | |||
| Name | Birth | Death | Joined with |
| James Kennedy (-c1408) | Scotland | 1408 Scotland | Mary Stewart (c1383-) |
| Alexander Kennedy | |||
| Hugh Kennedy | |||
| John Kennedy, 1st of Blairquhan (-1476) | Scotland | 1444 Scotland | |
| Thomas Kennedy | |||
| David Kennedy | |||