William de Ferrers, 5th Earl of Derby

William III de Ferrers, 5th Earl of Derby (c. 1193 – 28 March 1254) of Chartley Castle in Staffordshire, was an English nobleman and major landowner, unable through illness to take much part in national affairs.

From his two marriages, he left numerous children who married into noble and royal families of England, France, Scotland and Wales.

He was accidentally thrown from his litter into the River Great Ouse while crossing a bridge at St Neots in Huntingdonshire and, although he escaped death, never recovered from the effects of the accident.

The death in 1232 of his uncle Ranulf de Blondeville, 6th Earl of Chester, brought him vast new estates, including Chartley Castle in Staffordshire, much of Lancashire between the Rivers Ribble and Mersey and many manors in Northamptonshire and Lincolnshire.

He continued the policy of encouraging the growth of towns and markets, exploiting the forests of Needwood and Duffield Frith, and taking advantage of rising prices in commodities and land values.

Effigy of William de Ferrers, 5th Earl of Derby in Merevale Abbey , Warwickshire
Arms of William de Ferrers, 5th Earl of Derby: Vairy or and gules, a bordure azure (or sable) charged with eight horseshoes argent [ 1 ]
Arms of de Quincy : Gules, seven mascles or conjoined 3:3:1 . These arms were adopted by the descendants of William de Ferrers, 5th Earl of Derby and his wife Margaret de Quincy (see Baron Ferrers of Groby ), in lieu of their paternal arms of Vairy or and gules