Lord Sinclair is a title in the Peerage of Scotland

Peerage of Scotland

The Peerage of Scotland is the division of the British Peerage for those peers created in the Kingdom of Scotland before 1707. With that year's Act of Union, the Kingdom of Scotland and the Kingdom of England were combined into the Kingdom of Great Britain, and a new Peerage of Great Britain was...

. It was created in 1449 for William Sinclair, 3rd Earl of Orkney

William Sinclair, 1st Earl of Caithness

William Sinclair , 1st Earl of Caithness , 3rd Earl of Orkney , Baron of Roslin was a Scottish nobleman and the builder of Rosslyn Chapel, in Midlothian....

. In 1470, Lord Orkney surrendered the earldom in return for the earldom of Caithness

Earl of Caithness

Earl of Caithness is a title that has been created several times in the Peerage of Scotland, and has a very complex history. Its first grant, in the modern sense as to have been counted in strict lists of peerages, is now generally held to have taken place in favor of Maol Íosa V, Earl of...

. In 1477, Lord Caithness wished to disinherit his eldest son from his first marriage to Lady Elizabeth Douglas, William Sinclair (d. 1487), who was known as "The Waster". Therefore, so that his earldom would not pass to him, he resigned the title in favour of his son from his second marriage to Marjory Sutherland, who was also named William Sinclair (d. 1513) (who became the second Earl of Caithness). However, Lord Caithness was succeeded in the lordship of Sinclair by his eldest son William Sinclair, 2nd Lord Sinclair. The latter's son Henry, the third Lord, was confirmed in the title in 1488.

On the death of his great-great-great-grandson, the ninth Lord, the male line of the second Lord failed. He was succeeded by his grandson, the tenth Lord, the son of Catherine Sinclair, Mistress of Sinclair, daughter of the ninth Lord, and her husband John St Clair. In 1677 he obtained a new charter of the peerage confirming him in the title and with remainders respectively to his brother Henry Sinclair and his father's brothers Robert St Clair, George St Clair and Matthew St Clair, and failing them to his own heirs male whatsoever. However, his eldest son and heir John Sinclair, Master of Sinclair, was involved in the Jacobite rebellion of 1715 and attainted by Parliament. Consequently, he was not allowed to assume the title.

He died childless in 1750 when the claim to the title passed to his younger brother General James St Clair

James St Clair

General The Hon. James St Clair , was a Scottish soldier and Whig politician.-Background:St Clair was the second son of Henry St Clair, 10th Lord Sinclair and his wife Grizel Cockburn, daughter of Sir James Cockburn, 1st Baronet...

 (d. 1762). However, he never assumed the title. On his death the lordship became dormant. It was to remain so until it was successfully claimed by Charles Sinclair, 13th Lord Sinclair, who was confirmed in the title by the House of Lords in 1782. He was the son of Andrew St Clair, de jure 12th Lord Sinclair, grandson of Charles Sinclair, de jure 11th Lord Sinclair (d. 1755) and great-grandson of the aforementioned Matthew St Clair, uncle of the tenth Lord. He thereby became the first holder of the title without descent from the original Lords. The thirteenth Lord, his son the fourteenth Lord, grandson the fifteenth Lord, great-grandson the sixteenth Lord, and great-great-grandson the seventeenth Lord, all sat in the House of Lords as Scottish Representative Peers

Representative peer

In the United Kingdom, representative peers were those peers elected by the members of the Peerage of Scotland and the Peerage of Ireland to sit in the British House of Lords...

. As of 2009 the title is held by the latter's only son, the eighteenth Lord, who succeeded on his father's death in 2004.

Lords Sinclair (1449)

• William Sinclair, 1st Earl of Caithness and 1st Lord Sinclair
  William Sinclair, 1st Earl of Caithness
  William Sinclair , 1st Earl of Caithness , 3rd Earl of Orkney , Baron of Roslin was a Scottish nobleman and the builder of Rosslyn Chapel, in Midlothian....
  
   (d. 1480)
• William Sinclair, 2nd Lord Sinclair (d. 1487)
• Henry Sinclair, 3rd Lord Sinclair (d. 1513)
• William Sinclair, 4th Lord Sinclair (d. 1570)
• Henry Sinclair, 5th Lord Sinclair (1528–1601)
• Henry Sinclair, 6th Lord Sinclair (1581–1602)
• James Sinclair, 7th Lord Sinclair (d. 1607)
• Patrick Sinclair, 8th Lord Sinclair (d. 1615)
• John Sinclair, 9th Lord Sinclair (1610–1676)
• Henry St Clair, 10th Lord Sinclair (1660–1723)
  • John St Clair, Master of Sinclair
    John St Clair, Master of Sinclair
    John St Clair, Master of Sinclair was a Scottish noble and Tory politician.-Background:He was the older son of Henry St Clair, 10th Lord Sinclair and his wife Grizel Cockburn, eldest daughter of Sir James Cockburn, 1st Baronet...
    
    (1683–1750) (eldest son of tenth Lord; attainted in 1715 and never allowed to assume title)
  • James St Clair
    James St Clair
    General The Hon. James St Clair , was a Scottish soldier and Whig politician.-Background:St Clair was the second son of Henry St Clair, 10th Lord Sinclair and his wife Grizel Cockburn, daughter of Sir James Cockburn, 1st Baronet...
    
    (d. 1762) (younger son of tenth Lord; never assumed title)

dormant 1762–1782

• Charles St Clair, de jure 11th Lord Sinclair (d. 1775)
• Andrew St Clair, de jure 12th Lord Sinclair (1733–1775)
• Charles St Clair, 13th Lord Sinclair (1768–1863) (confirmed in title 1782)
• James St Clair, 14th Lord Sinclair (1803–1880)
• Charles William St Clair, 15th Lord Sinclair (1831–1922)
• Archibald James Murray St Clair, 16th Lord Sinclair (1875–1957)
• Charles Murray Kennedy St Clair, 17th Lord Sinclair (1914–2004)
• Matthew Murray Kennedy St Clair, 18th Lord Sinclair (b. 1968)