Cavendish Family History

English: habitational name from a place in Suffolk named Cavendish from an Old English byname Cāfna (meaning ‘bold daring’) + Old English edisc ‘enclosed pasture’. Cavendish is the surname of the Dukes of Devonshire. They are descended from Sir John Cavendish who served as Chief Justice of the King's Bench (1372–81).

Under the Tudors and Stuarts, a succession of shrewd and powerful heads of the family achieved political prominence and became extremely wealthy. William Cavendish, 2nd Earl of Devonshire, was a strong supporter of the ‘Glorious Revolution’ of 1688 and of William of Orange (William III) against James II.

In 1694 he was created Duke of Devonshire. The Latin family motto Cavendo tutus ‘safe through taking care’ is a pun on the surname.

Manx: Anglicized form of Corjeag, a shortened form of Mac Quartag ‘son of Svarteygr’ (from Old Norse meaning ‘black-eyed’). Folk etymology interpreted Corjeag incorrectly as Manx curjeig ‘alms-dish’ and equally incorrectly supposed that the surname Cavendish was a synonym meaning ‘giving-dish’.

Manxmen's familiarity with the English surname presumably led to the substitution.