The Chief Justice was born in 1350, temp. Edward III., at Gawthorp, in the parish of Harwood, between Leeds and Knaresborough.

Sir William was the eldest of five brothers. He married twice: first, Elizabeth, daughter and heiress of Alexander Mowbray, and by her had an only son, Sir William Gascoigne, of Gawthorp, a brave commander in the wars under King Henry V. His descendant, the last Sir William of this branch, married Beatrice, daughter of Sir Richard Tempest, and had four sons, all of whom died young, and one daughter, Margaret, his sole heir, in whom the Gascoignes of this line terminated. This daughter married, in 1552, Thomas Wentworth, of Wentworth Woodhouse, in Yorkshire, and brought great estates into that family. Thomas Wentworth was Sheriff for Yorkshire in the twenty-fourth year of Queen Elizabeth, and had, besides four daughters, an only son, who became afterwards Sir William Wentworth, and was the father of Thomas, first Earl of Strafford.

The Chief Justice married, secondly, Joan, daughter of Sir William Pickering, and widow of Sir Ralph Graystock, Baron of the Exchequer. By this marriage Sir William had also an only son, James Gascoigne, settled at Cardington, in Bedfordshire. A descendant of this James Gascoigne, the inheritrix of Cardington, married her distant cousin William, a younger son of the Gascoignes of Gawthorp.

This William Gascoigne was Sheriff for Bedfordshire in 1506, temp. King Henry VII., and was Sheriff for Buckinghamshire in the fifth year of King Henry VIII. He was subsequently knighted by Henry VIII., and became Comptroller of the Household to Cardinal Wolsey; for the great Cardinal in many respects affected Royal state, and succeeded in having the chief offices of his household held by nobles, or by men of gentle birth. This branch of the Gascoignes also terminated in a daughter, Dorothy, who married Sir Jarrett Harvye; thus the direct descendants of the famous Chief Justice became merged in other families. Of collateral descendants, however, there are many; Nicholas Gascoigne of Lavingcroft, Sir William's next brother, having left a numerous family of sons and daughters, who married amongst the Percys, Latimers, Vavasours, etc.

From the eldest son of this Nicholas descended a somewhat celebrated man, Richard Gascoigne, who was not only a learned antiquary and collector, but who has done good service to the history of this country by having brought before the public in 1638 Mr. Dugdale, whose writings have given much interesting and important information.

The greater part of the valuable collections made by Richard Gascoigne is now at Wentworth Woodhouse, Yorkshire. There are also relics of the Gascoigne family at Ickwellbury, Bedfordshire.

William Gascoigne became a student of the Law at Gray's Inn, and was early enrolled a member of that learned Society. His career was both brilliant and rapid. Towards the end of the reign of King Richard II. he was already so eminent in his profession that, in 1398, he was made one of the King's Serjeants.

There are records of many transactions at this period, all of which give proof, not only of Gascoigne's great abilities as a lawyer, but also testify to the esteem in which he was held on account of the fidelity and uprightness of his advice, and the invariable justice of his decisions. His great merits caused him to be appointed one of the Commissioners for Henry of Lancaster, Duke of Hereford, when this Prince was about to go into banishment.

Gascoigne had to watch over the interests and receive all moneys that might come to the Duke during his absence from England. A most onerous appointment, involving not only considerable difficulty but also no inconsiderable danger, for in those turbulent days the law of might frequently warred most successfully against the law of right.

So early as the second year of the reign of King Henry IV., Gascoigne was made Chief Justice of the King's Bench, and we find that in 1403 Judge Gascoigne and Ralph Nevill, Earl of Westmoreland, were commissioned by the King to levy and assemble forces in the counties of York and Northumberland in order to quell the insurrection of Henry Percy, Earl of Northumberland.