No certain record exists but it is likely that the Sinclairs came fromSaint-Clair-sur-Epte inNormandy.[1] According to traditional history, William of Saint-Claire accompaniedSaint Margaret of Scotland, daughter ofEdward the Exile toScotland in 1068, where she eventually marriedMalcolm III of Scotland. In return for his efforts, the king supposedly granted Sinclair the barony of Roslin "in free heritage".[2] However, according to late 19th century historian Roland Saint-Clair, it is not known if the people who held the estate of Roslin beforeWilliam St. Clair (died 1297), who is by tradition the 6th Baron, were actually of the same surname, and that he arrived in Scotland from Normandy in the 13th century.[3]William Sinclair (died 1480) who was the 11th Baron of Roslin was also the 3rdEarl of Orkney, 1stEarl of Caithness and 2ndLord Sinclair. He divided his estates: his eldest son from his first marriage,William, inherited the title of Lord Sinclair, while he left the Barony of Roslin to his eldest son from his second marriage,Oliver, and the earldom of Caithness to his second son from his second marriage, anotherWilliam, from whom descend the chiefs of theClan Sinclair.[4] The family of Roslin or Rosslyn prefer the spelling "St Clair" whilst the family of Caithness prefer the spelling "Sinclair".
Although theRosslyn Chapel tourist website refers to the early Barons by the spelling of Rosslyn,[5] most historic sources refer to them by the spelling of Roslin which is also used for the castle.[6][7] The laterEarls consistently appear with spelling of Rosslyn in accordance with the name of the chapel. The Rosslyn Chapel tourist website also refers to several of the early Barons as Princes of Orkney,[5] whereas most of the historic sources refer to them as Earls of Orkney.[8][9][7]
It is not known if the Sinclairs or St Clairs of Roslin share a common origin with the Sinclairs or St Clairs who held the title ofLord Herdmanston.[10]Herdmanston inEast Lothian had been held from the 12th century, when Henry St Clair received a grant of the lands of Herdmanston, fromRichard de Morville, Constable of Scotland.[2] According to the website sinclairgenealogy.info, the fact that the first proven Baron of Roslin, William St. Clair (died 1297) was made sheriff ofHaddington in East Lothian where Herdmanston also is, suggests that he was appointed there to cover his own home area, and given that the name William appears frequently in the St Clair of Herdmanston family suggests that he may have been part of their extended family.[11] However, according to the website clansinclairusa.org, William St Clair of Roslin was probably unrelated to the St Clairs of Herdmanston.[12] According to Archibald Allan writing in 1900, Henry St Clair of Herdmanston appears to have been a son of the first William de St Clair of Roslin of the 11th century,[13] but this William's existence cannot be proved by contemporary evidence and according to Roland Saint-Clair, William St. Clair who died in 1297 was the first proven Baron of Roslin.[3]
William St Clair of Roslin (succeeded in 1707 and died in 1778. All of his sons died young and he was succeeded by his daughter Sarah, who married Peter Wedderburn of Chester Hall. Their son was Alexander Wedderburn St Clair, 1stEarl of Rosslyn.)[5]
