William Sinclair, 1st Earl of Caithness

William Sinclair
Earl (Jarl) of Orkney Earl of Caithness Lord Sinclair Baron of Roslin
Earl of Orkney, Earl of Caithness, Lord Sinclair and Baron of Roslin Coats of Arms
Predecessor	Henry II Sinclair, Earl of Orkney
Successor	William Sinclair, 2nd Earl of Caithness William Sinclair, 3rd Lord Sinclair Oliver St Clair, 12th Baron of Roslin
Died	c. 1480
Noble family	Clan Sinclair
Father	Henry Sinclair, 2nd Earl of Orkney
Mother	Egidia Douglas

William Sinclair (1410–1480), 1st Earl of Caithness (1455–1476), last Earl (Jarl) of Orkney (1434–1470 de facto, –1472 de jure), 2nd Lord Sinclair and 11th Baron of Roslin was a Norwegian and Scottish nobleman and the builder of Rosslyn Chapel, in Midlothian.^[1]

In The Scots Peerage by James Balfour Paul he is designated as the 1st Lord Sinclair,^[2] but historian Roland Saint-Clair designates him the 2nd Lord Sinclair in reference to his father, Henry II Sinclair, Earl of Orkney, being the first person recorded as Lord Sinclair by public records.^[3]