Lord John Grey's son Sir Henry Grey was in 1603 raised to the Peerage of England as Baron Grey of Groby, "in the County of Leicester". He was succeeded by his grandson, the second Baron, who was created Earl of Stamford in the Peerage of England in 1628. Lord Stamford later fought as a Parliamentarian in the Civil War. His eldest son Thomas Grey, Lord Grey of Groby, was a leading Parliamentarian in the Civil War. Stamford was one of the judges at the trial of Charles I and one of the regicides who signed the King's death warrant. He predeceased his father and never succeeded to the earldom. Lord Stamford's daughter Lady Elizabeth Grey married George Booth, 1st Baron Delamer, and was the mother of Henry Booth, 1st Earl of Warrington. Stamford was succeeded by his grandson Thomas, the second Earl and the only son of Lord Grey of Groby. Thomas Grey was a politician and served as Chancellor of the Duchy of Lancaster and as President of the Board of Trade. He was childless and on his death in 1720 the titles passed to his first cousin Harry, the third Earl. He was the son of the Hon. John Grey, younger son of the first Earl.