This family is of Norman origin. In the 12th century William de Sancto Claro received the Barony of Midlothian. In the 14th century Henry St Clair became Earl of Orkney. The 3rd Earl, in 1446, founded Rosslyn Chapel. In 1445 he was created Earl of Caithness and the Earldom of Orkney was resigned in 1470. The Sinclairs were frequently engaged in clan warfare with Gunns. They were powerful and influential in the north where they held high positions. Sir John Sinclair of Ulbster, who died in 1835, was a noted agriculturalist and writer. His best-known work was the editing of the first Statistical Account of Scotland.