William de Ferrers (c. 1240-1287) of Groby Castle in Leicestershire was the younger son of William de Ferrers, 5th Earl of Derby (c.1193-1254) of Chartley Castle in Staffordshire, by his second wife Margaret de Quincy, daughter and heiress of Roger de Quincy, 2nd Earl of Winchester (c.1195-1264).
He founded the line of Ferrers of Groby, having been given Groby Castle by his mother Margaret de Quincy.
[2] Having rebelled against King Henry III, he was taken prisoner at the Battle of Northampton in 1264, but was later pardoned.
[3] In 1282 He was with King Edward I in the Army of Wales.
He married twice: