The estate of Dun is in the parish of Watten.
There is difficulty in determining with certainty the origin of the Sinclairs of Dun, but they are believed to be cadets of the Caithness family.
In a notice in Calder's "History of Caithness" they are said to have settled in Caithness in 1379, and to have possessed the lands of Dun nearly a century before any others of the name appear to have acquired a footing in the county. But no evidence has been found to support this view; and there is no reason given for fixing on so early a date as the period of the settlement of this branch of the Sinclairs in Caithness; nor indeed does it appear "that the name had any connection with the county till after the grant of the earldom in 1456", as stated by Mr. Alexander Sinclair. (Letter, March 1867) On the other hand, it is certain that in 1508, and even at a much later period, the lands of Dun were possessed by the Caldells or Calders, and there is no trace of a "Sinclair of Dun" sooner than 1540. In that year, as appears from an old inventory of titledeeds of the Groats, which is given by Calder, one "John Sinclair of Dun" was, along with other "honest men", a witness to a deed granted by the Earl of Caithness. In 1541 "David Sinclair of Dunn" was cautioner in a tack of teinds to the Earl of Caithness, and in 1544 "William Caldall of Dunn" is witness to an instrument of sasine in favour of Margaret and Helen Brisbane.
In a MS. written about 1770, by the late William Sinclair of Freswick, who was himself a descendant of the family of Dun, their progenitor is said to have been David, second son of William, second Earl of Caithness. In a charter granted in January 1560, to David Sinclair, then of Dun, by John, fifth Earl of Sutherland, and his wife Eleanor, they styIe him, "noster consanguineus-germanus"; but even on the supposition at one time generally entertained by genealogists, though now discarded, that Lady Marjorie, the mother of William, second Earl of Caithness, was cousin-german, or, as she is called by Gordon, "near cousin", to Elizabeth, Countess of Sutherland (the grandmother of Earl John), David, the supposed son of the Earl of Caithness, would only, after all, stand to Earl John in the degree of third cousin. If, however, as stated in the notice in Calder's "History", the relationship between David Sinclair of Dun and Earl John was merely that of "cousins by consanguinity", that requirement is no doubt met if David Sinclair really was the son of Earl William. But Earl William's only sons of whom we have certain mention are John, his successor, Alexander of Stemster, and William, a natural son, who was legitimized in 1542. How then David of Dun and Earl John could have been cousins-german, remains to be explained.
In a MS. on Caithness affairs by the late Captain Kennedy of Wick, it is said that "George, fourth Earl of Caithness, had a son called David, who begat John Sinclair of Dun and William Sinclair of Forss-Milns". This, if true, might account for the John Sinclair of 1540, mentioned in Groat's Inventory; but then there is no evidence that the fourth Earl had a son named David, although he had a natural brother, David Sinclair, who was Bailie to the Bishop of Caithness, and who appears in 1541 as cautioner for the Earl in a tack of the teind sheaves of Canisbay, and who is likewise mentioned as having been imprisoned by his brother in Girnigo Castle.
About the middle of the sixteenth century, and probably not later than 1557 or 1558, George, the fourth Earl, arranged a marriage between Y McKay of Farr, and Christian Sinclair, who is designed by Gordon as "daughter to the laird of Dun, and cousin to the Earl:" It is evident that, if this lady was the Earl's cousin only, the Earl could not have been the father of this laird of Dun. McKay, referring to this marriage, says (p. 152), that Christian Sinclair was the daughter of "Williarn Sinclair, laird of Dun", and that she was the Earl's cousin. If Earl George's illegitimate uncle, William, the son of William, the second Earl, was laird of Dun, then Christian Sinclair and Earl George were certainly cousins-german; but there appears to be no evidence that Christian Sinclair's father was named William, although so stated by McKay.
In the above-mentioned charter granted to David Sinclair of Dun, in 1560, the Earl of Sutherland gives to him in liferent, and to "his sons", William, Alexander, and Henry, in succession, and to the "heirs-male of their bodies lawfully begotten", in fee, the lands of Forss and Baillie. It appears that in 1586 a Henry Sinclair, who unquestionably was the brother of Christian, the laird of Dun's daughter, was killed in a fight with the Clan Gunn, then under command of Hutcheon McKay, who was a son of Christian Sinclair, and therefore Henry's own nephew. As no other Henry Sinclair is mentioned about the same period, except Henry, the son of David of Dun, it may be that. Christian Sinclair's brother was the same Henry Sinclair who is named in the charter, and thus that she was a daughter of David Sinclair of Dun. If so, as she was "cousin to the Earl of Caithness", so must her father also have been connected with that family.
There is extant a summons dated 12th March, in the 20th year of Queen Mary - that is the year 1562 - at the instance of John Sinclair, "eldest son and heir of the deceased David Sinclair of Dun", with consent of his curators, the Earl of Caithness and John Grote, against William Sinclair of Forss, as an intromitter with the writs and evidents of David Sinclair; immediately after his decease in March 1560. In this action William Sinclair is called upon to produce acquittances given to David Sinclair of Dun by the Executors of James Brodie, Archdeacon of Caithness, for rents due by the tenants in the temporal lands of the Arch-deanery, from 1547 to 1558; acquittances from 1528 to 1560, by the Bishop, for the teind sheaves of Staneland, Forss, and Baillie, and for the maills and duties of the temporal lands of the bishopric, and fitted accounts between the Bishop and David Sinclair of Dun, of his intromissions with the farms and duties of the earldom of Caithness. If David Sinclair had been the Chamberlain or Bailie of the Bishopric, the writs which William Sinclair is called upon to produce, as taken by him from the repositories of the deceased, are just such documents as David would properly have had in his possession; and it has been shown that David, a son of John, Earl of Caithness, actually held the office of Bailie to the Bishop. As this Earl lived till 1529, there is no difficulty in supposing his son to have lived till 1560; and thus, the father of John Sinclair of Dun of 1562, may have been David, the natural son of Earl John.
The summons makes no reference to any relationship between David Sinclair of Dun and William Sinclair of Forss; and thus, while it is certain that the latter was a son of the David Sinclair of Dun who got the charter in January 1560, and that John Sinclair was the son of a David Sinclair of Dun who died in March 1560, still it is not known that the two Davids were identical, and that William Sinclair of Forss and John Sinclair of Dun were brothers.
If the circumstance that John Sinclair sues, in 1562, with consent of curators, is to be taken as proof that he was then a minor, it is difficult to reconcile the fact of his having been the eldest son and heir of his father, with his being brother to William Sinclair of Forss, for the latter in 1561 had been admitted as vassal in Forss to the Earl of Sutherland; had granted deeds as owner in possession of these lands; had been witness to the execution of important deeds, and had thus conducted himself as a man of full age. But if the David Sinclair who got the charter in January 1560, and the David Sinclair who died in March of the same year, were the same, then William of Forss and John of Dun must have been brothers, and William Sinclair and his brothers, Alexander and Henry, may have been sons by a previous marriage, and John may have been made the heir to the Dun estate under some family arrangement similar to that by which William was provided with Forss and Baillie. Or, lastly, David Sinclair m.ay have had an elder son, David, who, after succeeding to Dun, had died young and left his son and heir, John, a minor, who would thus be the nephew of William Sinclair, and not his brother. Among the writs taken possession of by William Sinclair, the summons of exhibition includes a contract between David Sinclair of Dun and the Master of Oliphant, in regard to these lands, by which the Master, who had in 1549 obtained a grant of the nonentry dues of Dun, obliged himself to give a new infeftment thereof. This deed, if it be still in existence, would no doubt throw some light on the history of the family.
Finally, there is an account of this family in Father Hay's "St. Clairs of Roslyn". It is there said: "St. Clair of Doun is a great-grand-child of John, Lord Beridall. The first of this surname who obtained these lands was one David, who married one Marie, heretrix of Doun, daughter to William Caldar, and begot John, who espoused Agatha, daughter of Heugh Grant or Grott of Souldon, upon whom he begott William, who espoused Margaret, daughter of Sir William Keith of Loutquarne, by whom he had several childering: they all dieing, their uncle, William, second sone to the foresaid John and Agatha, succeeded, and married Marjorie, daughter to Saul Bruce, Laird of Leith (Lyth), who bore to him David, his successor, married upon Janet, daughter of John Saintclare of Olbstar. This David was laird of Doun".
It is noticeable that these various accounts of the origin of the family, with the exception of the incidental reference to John of 1540, all point to a David Sinclair as the first laird of Dun, although they differ as to his paternity. But if Hay's "David, laird of Dun", who married Ulbster's daughter, was the son, as he is supposed to have been, and not the grandson of John Sinclair, as his pedigree of the family makes him to be, then this David Sinclair might have been" the great-grand-child of John, Lord Beridall" (afterwards third Earl of Caithness), and the grandson of the Earl's natural son, David, the Bishop's Bailie. Mr. Alexander Sinclair (Ulbster), who has given much attention to genealogical subjects, writes in March 1867, "I always thought that Dun came from David, son of John, third Earl of Caithness".
II. JOHN SINCLAIR, eldest son and heir of David, succeeded him in these lands. In 1591 he was infeft on a charter by the Earl of Caithness, and in 1592 he got a Crown charter of confirmation. He was twice married, and had by his first wife, whose name is unknown, three sons: -
His second wife was Margaret, daughter of Donald Sutherland of Forse, who was styled "Lady Dun". She survived her husband and afterwards married Charles Calder of Lynegar.
By his first marriage David Sinclair had three sons; and by his second marriage, a daughter: -
V. William Sinclair of Dun was served heir of provision to his brother, Francis, and in 1663 he got a charter from the Archdean of Caithness of Scarmclett, Larrel, Galshfield, Clayock, and Campster. He was three times married, first in 1643, to Elizabeth, daughter of Alexander Sutherland of Forse; secondly, to Isabel, daughter of John Sinclair of Assery; and thirdly, to Katharine Sinclair, "Lady Dun", daughter of Alexander Sinclair of Telstane. He had two sons and two daughters: -
VI. Alexander Sinclair of Dun received a disposition from his father in 1680. He was twice married. The name of his first wife has not been ascertained. His second wife was Barbara, youngest daughter of Alexander Henderson in Gerston, whom he married in 1751, but he had no issue by her. He died in 1754. He had four sons and two daughters: -
The story in Calder's "History of Caithness" (p. 259) that the possessor of Dun in 1745 shot himself, because balked by his mother in keeping an engagement to join the Stewart party, is certainly without foundation, but whether William, the eldest son and apparent heir in 1731, was alive in 1745 is uncertain.
Nisbet, whose work on Heraldry was written early in last century, mentions from the Lyon Register the Arms of a "Thomas Sinclair, descended from the family of Dun in Caithness", but of him there is no trace. The crest was "a demi-man holding in one hand a sea-cat, and in the other a pair of pencils, all proper", and the Motto, "Sic rectius progredior". In the Register the name is Lawrence, [and Nisbet's "sea-cat" is "a seacart", i.e. sea-chart]. He also mentions the Arms of a "Thomas Sinclair, son of William Sinclair, merchant in Thurso, descended of the family of Caithness:" Motto, "Fear God and Live"; but whether this is the same or a different Thomas Sinclair, does not appear.
The Arms of William Sinclair of Dun were argent, a cross ingrailed sable within a bordure of the second, charged with eight plates argent: Crest, a man on horseback proper. Motto "Promptus ad certamen".