E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
One dubbed at Court by favour, not having won his spurs by military service in the field. Mayors, lawyers, and other civilians knighted as they kneel on a carpet before their sovereign. Knights of the Carpet, Knights of the Green Cloth, Knights of Carpetry.
The subordinate commands fell to young patricians, carpet-knights, who went on campaigns with their families and slaves.Froude: Csar, chap. iv. p. 91.