3rd Lord Ferrers of Groby, of Groby (in Ratby) and Thurnby, Leicestershire, Marks (in Dunmow), Stebbing, Woodham Ferrers, Essex, Newbottle, Northamptonshire, Lidlow and Stokie upon Tern, Shropshire, etc.
Sir William Ferrers was born on 28 February 1333 at Newbold Verdon, Leicestershire, England. He was christened at Newbold Verdon, Leicestershire, England.
Marriage & Children
He married, firstly, Margaret de Ufford, 3rd daughter of Robert de Ufford, K.G., 1st Earl of Suffolk, Lord Ufford before 25 April 1344. They had 1 son & 2 daughters:
Sir Henry, 4th Lord Ferrers of Groby
Elizabeth, a nun
Margaret, wife of Sir Thomas Beauchamp, 12th Earl of Warwick
He married, secondly, Margaret de Percy, widow of Robert de Umfreville, Knt. (living 1340, died before 1347) before 25 May 1368.
William was with the king in the invasion of France in October 1359-1360. 
He was summoned to Parliament from 15 March 1353/4 to 6 April 1369 
In 1354 he put forward his hereditary claim to the manors of Chorley and Bolton, Lancashire against Alice widow of Robert de Shireburne, Knt., John de Harington, Knt. and his wife, Katherine, and Thomas de Arderne, nt. His claim was prosecuted for many years, when he regained the Arderne moiety probably by some agreement or compromise.
In 1356 he granted his moiety share of the manor and vill of Ludlow, Shropshire to his cousin, Roger de Mortimer, 2nd Earl of March, in exchange for the manor of Long Crendon, Buckinghamshire. 
The fourth shield has—Ferrers of Groby impaling Ufford, sable, a cross engrailed or. Inscription: “William Ferrers, the fourth Lord Ferrers of Groby, maried Margaret, daughter of William Ufford, Earle of Suffolk.” 
Sir William Ferrers left a will on 1 June 1368; Requested burial at the conventional church at Ulverscroft, Leicestershire. He died on 8 January 1371 at Stebbing, Essex, England, at age 37. His estate was probated on 19 July 1372.
Royal Ancestry by Douglas Richardson Vol. IV page 351
I recognise this 'Ferres' being the ancestors of the Ferris family. Amelia Ferris was my 3 x great grandfather - married to George David Appleton in New Zealand.
I have also found the Spencer family, including our present HRH through marriage. Our infamous ancestor is also John 'Lackland', the King on the throne from about 1199 AD. I have a profile on Ancestry which I have always used if anyone would wish to access it.
Please contact me on firstname.lastname@example.org
De Ferrier-5 and Ferrers-27 appear to represent the same person because: they have the same wife. If you agreed that these are duplicate profiles for the same person, please merge them into Ferrets-27. Thank you.
No sources list Ann as a daughter of this William Ferrers. There is an Ann, daughter of William Ferrers who married Sir Edward Despenser. but, she married in 1335, which would be when this William was 3 years old.