Background
She was the daughter of William Stourton, 2nd Baron Stourton and Margaret Chidiock. Her father, although not a leading political figure, enjoyed the confidence of Edward IV: in 1469 he sat on the commission of oyer and terminer which condemned Thomas Hungerford of Rowden and Henry Coutenay to death for treason. About 1475 Katherine married Sir William Berkeley, son of Sir Maurice Berkeley of Beverstone Castle, Gloucestershire.
At about the same time her brother John married William"s sister.