http://en.wikipedia.org/wiki/Judith_of_Lens

Countess Judith , was a niece of William the Conqueror. She was a daughter of his sister Adelaide of Normandy, Countess of Aumale and Lambert II, Count of Lens.
In 1070, Judith married Earl Waltheof of Huntingdon and Northumbria. They had three daughters, the eldest of whom, Maud, brought the earldom of Huntingdon to her second husband, David I of Scotland.
In 1075, Waltheof joined the Revolt of the Earls against William. It was the last serious act of resistance against the Norman conquest of England. Judith betrayed Waltheof to her uncle. Waltheof was executed by decapitation on 31 May 1076.
After the execution of her Waltheof, Judith was betrothed by William to Simon I of St. Liz, 1st Earl of Northampton. Judith refused to marry Simon and she fled the country to avoid William's anger. He then confiscated all of Judith's English estates.
Judith founded the Abbey at Elstow Bedfordshire in about 1078. She also founded churches at Kempston and Hitchin.
She had land-holdings in 10 counties in the Midlands and East Anglia. Her holdings included land at:
▪ Earls Barton
▪ Great Doddington
▪ Grendon
▪ Potton
Sawtry Judith is named after the Countess.