Rainsford was the second son of Robert Raynsford of
Staverton, Northamptonshire and his second wife Mary Kirton, daughter of Thomas Kirton of
Thorpe Mandeville Northamptonshire. He matriculated at
Exeter College, Oxford on 13 December 1622, but left the university without a degree. He was knighted by 1622. In 1630 he was elected recorder of
Daventry, being then a student of
Lincoln's Inn, where he was
called to the bar on 16 October 1632. In 1653 he was chosen
recorder of
Northampton. Rainsford was elected
Member of Parliament for
Northampton in April 1660 for the
Convention Parliament. In 1660 he became treasurer of Lincoln's Inn and on 26 October 1660 he was sworn
serjeant-at-law. He was one of those designated a member of the projected order of
Knights of the Royal Oak. He was re-elected MP for Northampton in 1661 for the
Cavalier Parliament, and sat until 16 November 1663 when he was raised to the bench as
Baron of the Exchequer. He presided over the commission which sat at Dublin during the earlier months of 1663 to supervise the execution of the
Act of Settlement 1662, and on his return to England was raised to the exchequer bench, 16 November the same year. Rainsford was one of Sir
Matthew Hale's colleagues in the commission which sat at
Clifford's Inn between 1667 and 1672, under the
Fire of London Disputes Act 1666 to determine the legal questions arising out of the rebuilding of the quarters of London destroyed by the great fire. In the meantime he was transferred to the king's bench, 6 February 1669, and on 12 April 1676 he succeeded Hale as
Chief Justice of the King's Bench. On the return to
Lord Shaftesbury's writ of
habeas corpus he decided, 29 June 1677, an important point of constitutional law, viz. that the courts of law have no jurisdiction, during the parliamentary session, to discharge a peer committed by order of the
House of Lords, even though the warrant of commitment be such as would be void if issued by an ordinary tribunal. Raynsford was removed to make room for
Sir William Scroggs in June 1678. Rainsford died on 17 February 1680 at
Dallington, Northamptonshire, where he had his seat and founded an almshouse. His remains were interred in Dallington church. ==Family==