From the longer Wikipedia page 
Katherine Neville, Baroness Hastings (1442 – between January and 25 March 1504), was a noblewoman and a member of the powerful Neville family of northern England. She was one of the six daughters of Richard Neville, 5th Earl of Salisbury, and the sister of military commander Richard Neville, 16th Earl of Warwick, known to history as Warwick the Kingmaker.
She was married twice. By her first husband William Bonville, 6th Baron Harington of Aldingham, she was the mother of Cecily Bonville, who became the wealthiest heiress in England following the deaths in the Battle of Wakefield of Katherine's husband, her father-in-law; and less than two months later, of William Bonville's grandfather, William Bonville, 1st Baron Bonville who was executed following the Yorkist defeat at the Second Battle of St Albans. Katherine's second husband was William Hastings, 1st Baron Hastings, a powerful noble who was beheaded in 1483 on the order of King Richard III, who placed Katherine directly under his protection.
King Edward died on 9 April 1483; his son Edward V and kingdom were placed under the guardianship of his youngest brother Richard, Duke of Gloucester who was made Lord Protector of England. It was Katherine's husband William Hastings who advised Richard to take the young King Edward V into protective custody immediately following the death of Edward IV.
It was about this time that Katherine's husband became the lover of Jane Shore, a former mistress of both the late King Edward and her son-in-law, Thomas Grey, 1st Marquess of Dorset. The latter had married her eldest daughter, Cecily in 1474. Hastings had confided to his mistress his concern that his considerable power and influence was on the wane under the protectorate of Richard. She encouraged him to enter into a conspiracy with the Woodville family against the Lord Protector. Richard, upon discovering Hastings' treachery ordered his immediate execution, which took place on 13 June 1483 at the Tower of London. Several weeks later, Richard sealed an indenture, swearing to take Katherine directly under his protection and to
"secure for her the enjoyment of her husband's lands, goods, privileges, and the custody not only of their heir until the boy came of age but also the wardship of the young Earl of Shrewsbury who was married to their daughter, Anne".
Richard assured Katherine that Hastings would never be attainted, and that she would be defended against any attempt by intimidation or fraud to deprive her of her rights.
Shortly after Hastings' death, on 22 June, Richard proclaimed himself King of England which was supported by an Act of Parliament known as Titulus Regius that declared his nephew King Edward V and his siblings illegitimate. He was crowned king on 6 July.
In spite of Richard's promise to uphold her interests, his close friend and ally, Francis Lovell, 1st Viscount Lovell claimed that the Hastings manors of Ashby and Bagsworth, and the Beaumont estates belonged to him, although these had been left to Katherine following her husband's execution. In order for Katherine to retain these properties, she was compelled to pay Lovell the sum of 200 marks in cash and give him lands totalling the same amount per annum. Richard made no move to curtail the avarice of his friend, who had assumed a powerful role in the government during the King's brief reign. King Richard was killed at the Battle of Bosworth on 22 August 1485 and the Lancastrian victor, Henry Tudor subsequently ascended the throne as Henry VII. Katherine's eldest surviving son, Edward fought on the side of King Henry against Lovell at the Battle of Stoke in June 1487. This battle saw the final defeat of the House of York and Lovell, as one of the Yorkists' chief leaders, afterwards fled to Scotland; however, his eventual fate remains unknown.