William Sinclair

William St. Clair, 6th Baron of Roslin (died 1297), was a Scottish nobleman of the late 13th century.

Origins According to Roland Saint-Clair, writing in the late 19th century, the "best" theory as to the origin of William St. Clair, is that found in the Genealogie of the Sainteclaires of Rosslyn manuscript which was written in 1690 by Father Richard Augustine Hay (1661 – 1736). According to this manuscript, William St. Clair, was the second son of Robert de Saint-Clair in Normandy who had married Eleoner who, in turn, was the relict of Hugh, Lord of Chateauneuf, and daughter of Robert II, Count of Dreux in France, by Yolande de Coucy. Roland Saint-Clair also stated that Van Bassan's History of the St. Clairs is "considerably at variance with contemporary annals". and the previous holders of Roslin, were unrelated to the St. Clairs.

Sheriffdoms According to Bernard Burke, William St. Clair, was made sheriff of the County of Edinburgh for life in 1271, However, according to Alexander Nisbet's Memorial of the ancient family of St Clair of Roslin, he became sheriff of the shire of Edinburgh in 1278 which was the 30th year of Alexander III of Scotland. The Exchequer Rolls of Scotland also show William St. Clair as being sheriff of various shires from 1264 to 1290, including: Haddington (1264–66), Linlithgow (1264), Edinburgh (1266), Dumfries (1288), Edinburgh (1288–90) and Linlithgow (1290). A charter of 1280 is the first evidence of the St. Clairs' connection with Roslin, and it is not clear if the people who held the property before then were of the same surname.

Wars of Scottish Independence In 1291, William St. Clair was appointed to take fealties in Galloway and in 1292, he was ordered by Edward I of England to take the fealty of the Bishop of Whithorn and Galloway. They were later permitted to support Edward I of England in his wars in France, as hostages, but Rotuli Scotiae shows that Sir William de St. Clair was among those who were sent as prisoners to the Tower of London. The History of the St. Clairs states that he was also one of the victorious leaders at the Battle of Roslin in 1302 or 1303 where the English were defeated.

Family William St. Clair, may have been "the Seemly St. Clair" who married Agnes, daughter of Patrick Dunbar, Earl of March. On 7 April 1299, Edward I of England issued two years' protection for Amicia, widow of William de St. Clair, dwelling by the king's leave in the county of Edinburgh. William St. Clair is known to have left the following children:

Sir Henry Sinclair, 2nd Baron of Roslin (heir and successor) William Sinclair, who was the Bishop of Dunkeld and the King's Bishop Gregory Sinclair, ancestor of the Sinclairs of Longformacus Annabel Sinclair, who married, firstly, Robert Bisset and, secondly, Sir David Wemyss