A 1616 pedigree of the Knightley family states, "Robertus de Plumpton, frater et heres Willielmi de Plumpton, dominus manerii de Plumpton. Azure five fusils in fess or, each charged with a mullet gules. [1]
[1] Joseph Jackson Howard, ed., "Pedigree of the Knightley Family of Fawsley, Co. Northampton, compiled by Augustine Vincent, from the original in the possession of Sir R. Knightley, Bart., M.P.," Miscellanea Genealogica et Heraldica, Vol. 1 (London: Hamilton, Adams, and Co., 1868), 88-102 at 91, [GoogleBooks], [HathiTrust].