From the Wikipedia page 
Sir Richard Ratcliffe (died 22 August 1485) was a close confidant of Richard III of England. He came from a gentry family in the Lake District, and became a companion of Richard when the latter was still Duke of Gloucester. He was one of Richard's trustees in the lordship of Richmond, and was named steward of Barnard Castle. Richard, while Duke of Gloucester, knighted Ratcliffe during the Scottish campaigns, at the same time creating him a knight banneret.
During the seizure of power by Richard III, Ratcliffe was chosen to return to the north and organize an army to help the Protector, as Richard III was then titled. Some sources name Ratcliffe as the person who gave the orders to execute Earl Rivers.
When Richard became king he gave Ratcliffe a number of offices, including the currently attainted hereditary High Sheriff of Westmorland, and made him a Knight of the Garter. He also received a large grant of lands, including much that had belonged to the Courtenay Earls of Devon. After the rebellion of 1483 he was given a very large number of forfeited estates. As a result he had an income larger than most. He married Agnes Scrope, daughter of Henry Scrope, 4th Baron Scrope of Bolton, one of the great barons in the north of England. (She was also the half-sister of the wife of William Catesby).
In July 1484, William Collingbourne, a Tudor agent, tacked up a lampooning poem to St. Paul's Cathedral which mentions Ratcliffe among the three aides to King Richard, whose emblem was a white boar:'The Catte, the Ratte and Lovell our dogge rulyth all Englande under a hogge.'
(The dog here refers to a Lovell family heraldic symbol.) Robert Fabyan, The New Chronicles of England and France in t[w]o Parts (London, 1811), p. 672, Bertram. Royal Blood: Richard III and the Mystery of the Princes. 2000. The poem was interpolated into Laurence Olivier's film Richard III, a screen adaptation of William Shakespeare's play.
Richard Ratcliffe was one of the two councilors (the other was William Catesby) who are reputed to have told the king that marrying Elizabeth of York would cause rebellions in the north. The Princes in the Tower p. 211-212,
He died at the Battle of Bosworth Field.