William was born in 1241.1 William's father was Roger de Calthorpe and his mother was <Unknown>. His paternal grandparents were Walter de Calthorpe and <Unknown>. He was an only child. He died at the age of 65 in 1306.1
General Notes
William de Burnham dying without issue, in the reign of Henry III, this lordship came to Sir William De Calthorp, by his marriage with the sister and heir, Cecilia, as may be seen in Harpley.