William, b. about 1380, was of Halstead, co. Essex, 3 Henry V, (1415). (Court Rolls, Honour of Clare, vol. 1859, p. 48.) His further history has not been traced, but perhaps he was father of John Coo who d. in 1452, progenitor of the Coes of Boxford and Groton, co. Suffolk, who bore the same coat-of-arms as the Coes of Gestingthorpe.
