Clan Sinclair of Scotland; descended from Henry St. Clair of England, who went to Scotland as Vicecomes to Richard Morville, Constable of Scotland in 1163. His family were originally from Saint-Clare-sur-Elle in Normandy. He was granted an estate in Herdmanstoun, Haddingtonshire and the title of baron. Sir William St. Clair, Sheriff of Edinburgh was granted the barony of Roslin in 1280. His son, Sir Henry, swore fealty to Edward I of England in 1296, and the family at first supported the Balliols but later joined Robert the Bruce, and they fought at Bannockburn in 1314. Sir Henry was rewarded with lands near Pentland in 1317.
The earldom of Orkney was conveyed to James III of Scotland in 1470. George Sinclair, 4th Earl of Caithness was a supporter of Mary, Queen of Scots, was implicated in the murder of Lord Darnley, presided at the trial of Bothwell and instigated acts of violence in northern Scotland. George, the sixth Earl of Caithness, was in great debt and mortgaged much of the family lands in 1672 to Sir John Campbell of Glenorchy who claimed the estates when Sir George died without issue in 1676. Campbell also married George’s widow and claimed the tite. George Sinclair of Keiss disputed the claim and led the Sinclairs into battle with the Campbells at Altimarlech near Wick, where they suffered severe losses. The Sinclairs regained the earldom in 1681 by an order of Parliament.
Arms: (Earldom of Orkney) Azure, a ship at anchor, oars in saltire and sails furled, within a double tressure flory counterflory or. (Arms of the Earldom of Caithness: Azure a ship under sail or, the sails argent) These two feudal coats are found marshalled with Sinclair of Rosslyn, in different ways by the Earls of Ockney and their descendants. The modern arms are: Arms: Quarterly, 1st, Azure, a lymphad at anchor or, flagged gules, sails furled argent, oars in saltire or, within a Royal Tressure or (Earldom of Orkney); 2nd and 3rd, Or, a lion rampant gules, armed and langued azure (Sparr-Nithsdale); 4th, Azure, a three masted ship or, flagged gules, under sail argent(Earldom of Caithness); overall a cross engrailed and counterchanged argent and sable (Sinclair).
Crest: A cock proper, armed and beaked or.
Motto: Commit thy work to God.