This interesting name is a variant of Sinclair and is locational from any of the places in France incorporating this name e.g. Saint-Clair-sur-Elle, in La Manche. "Sinclair, Sutherland, Keith, and Gunn, There never was peace when the four were in!". Apparently these neighbours found peace a difficult process in the 16th Century, the Sinclairs being a powerful Scottish territorial family, who held their lands under feudal power in Caithness and Orkneys. The name however is French and the first holder was a follower of William the Conqueror, and awarded lands in Somerset. Their first Scottish possession being The Baronny of Roslin, near Edinburgh in the 12th Century. Between 1379 and 1542, the Sinclairs held the Earldom of Caithness whilst the spellings have included Sanclar, 1493, Seinclere 1445, Sinklare 1640 etc. Sir William St. Clair of Roslin, circa 1330 is listed in the National Biography. The first recorded spelling of the family name is shown to be that of Hubertus de Sancto Claro. which was dated 1086, The Somerset Domesday Book. during the reign of King William I, The Conqueror, 1066 - 1087. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.