This surname is derived from a geographical locality. 'of St. Clair,' some chapelry in Normandy; compare Simbarb, St. John, &c.

John de Sanet Claro, Suffolk, 1273. Hundred Rolls.

Robert de Sancto Claro, Somerset, ibid.

William de Sancto Claro, Kent, ibid.

Richard Seinteclere, Somerset, 1 Edward III: Kirby's Quest.

William Seyncler, Somerset, 1 Edward III: ibid.

1611. Baptised — Helene, d. Nicholas Saynteleare: St. James, Clerkenwell.

1618. James Sinclar: Register of the University of Oxford.

1777. Married — John Sinclaire and Ann Holborn: St. George, Hanover Square.

This Caithness surname is of territorial origin from St. Clare in the arrondissement of Pont d'Eveque, Normandy. The first Sinclairs in Scotland appear to have been vassals of the great territorial magnates, de Morville. Their first possession in Scotland was the barony of Roslin, near Edinburgh, which they held in the reign of David I (11241153). The earliest bearers of the name appear in charters connected with the abbeys of Dryburgh and Newbattle, the Hospital of Soltre (now Soutra in Midlothian), the church of Glasgow, etc. An early offshoot of the family became all powerful in Caithness and held the earldom there from 1379 to 1542. The frequency of the surname in Caithness and in the Orkneys is due to the tenants on the lands of the earldom adopting the name of their overlord just as we find tenants who possessed no surnames of their own doing likewise elsewhere. The Sinclairs, like the Gordons and some other families, cannot be called a clan in the true sense of the term. They were a powerful territorial family, whose relationship to their dependents was entirely feudal. John Singular held land in Aberdeen, c. 1450 (REA., II, p. 298). Lassæ Saengkaer (Laurence Sinclair) who was burgomaster of Oddevald in 1504, appears again in 1508 as Laffris Saenckeller (Dipl. Norv., III p. 746,757). An old rhyme referring to the bickerings between the Sinclairs and their neighbors says:

"Sinclair, Sutherland, Keith, and Clan Gunn, There never was peace when thae four were in."Stolen from Fore-bears

Sanclar 1493, Santclar 1539, Santclere 1545, Santoclair 1407, Seincler 1261, Seintclere 1445, Seintclerk 1296, Seyntclere 1405, Sincklair 1634, Sincklar 1597, Sincklare 1684, Sinclder 1647, Sinclaire 1598, Sincler 1620, Singlar 1454, Singkler 1491, Sinkaller 1692, Sinkclair 1667, Sinklare 1640, Synclare 1482, Syncleir, 1528, Syncler 1544, Synclere 1470, Synklair 1526, Synklar 1529. In Argyllshire the name is used as an Englishing of Gaelic Mac na cearda.

(Anglo-French-Latin) belonging to St. Clair (several in Normandy) [French clair, Latin clar-us, clear, bright, illustrious] This name was Latinized in mediæval deeds de Sancto Claro.

Corruption of “St. Clair”.

(Scottish, English) One who came from St. Clair (bright), the name of several places in Normandy; follower of St. Clare.

A corruption of Saint Clair or Saint Clere.

A corruption of St. Clare. The family are descended from Walderness Compte de Saint Clare, who came into England with William the Conqueror; his son, William de Sancto Claro, settled in Scotland, where he obtained from Alexander I, a grant of the Barony of Roslyn.

A corruption of Si Clair, and that from St Clara, from the Latin clarus, pure, renowned, illustrious.

Sinclair: is also a family and name of Norman origin. The Sire de St. Claire is named in the “Roman de Rou” as having been present at the Battle of Hastings. This was Richard de St. Clair. His brother was Britel, and it was in all probability William Britel’s son who received the grant of Rosslyn in Midlothian from David I. From him are descended the Sinclairs, Earls of Orkney and Caithness. Besides William, another of the family sought his fortunes in Scotland, Henry de St. Clair, who was made Constable of Scotland in 1160, and was the founder of the House of Herdmanston, now represented by Lord Sinclair.