Sir Laurence fitz Richard de Cornwall

Lawrence is not listed on Wikipedia as the son of Joan de Valletort and Richard Plantagenet, Earl of Cornwall's son. He is believed to be by an earlier, unnamed mistress of Richard, Earl of Cornwall. Many people from Cornwall took its name to be their surname, and thus were named "de Cornwall" not because they were all illegitimate children of the Earl but because they were born there. But in this case Laurence has been referred to in documents as Sir Laurence Fitz Richard of Cornwall.

There is proof that Richard, Earl of Cornwall had a son named Laurence and this comes from a document held at Cornish Archives Ref : AR/1/842 where Laurence witnessed a document for Richard, Earl of Cornwall where Laurence is described as Laurence,son of Richard.

Laurence Fitz Richard of Cornwall was born about 1227 and his wife was Helen.

Laurence was a knight to William de Lancaster (d. 1246) and was present at his deathbed.

“ Lawrence de Cornwall (from Hudleston pedigrees)” Michael Andrews-Reading post at SGM (2004) < link >

Hudleston & Boumphrey's Cumberland Families & Heraldry, p 191 refers to "Sybel (living 1343) daughter of Lawrence de Cornwall or de Kirkby, married before 1279 Sir John Hudleston, of Millom (died before 1306)...argent, two bars gules, on a canton of the last a cross moline or." Sir John is said (p 170) to be ancestor of the Hudlestons of Millom.