Lovell succeeded to his father's titles and estates at the age of nine years old. He became a ward of Edward IV of England, who gave him into the charge of the Earl of Warwick, in whose household Richard also spent some time. It was there that the two young men first formed their close association.
Upon the death of his paternal grandmother in 1473 he inherited a large estate, including the lands of the baronies of Deincourt, Grey of Rotherfield, and the feudal barony of Bedale. He was now one of the wealthiest barons in England not holding an earldom or dukedom.
He served as a young man under Richard in the expedition to Scotland in 1480, and was knighted by Richard for it, the same year. After the death of Edward IV on 9 April 1483 he became one of his patron’s strongest supporters. He had been created a viscount on 4 January 1483, and while still Lord Protector Richard made him Chief Butler.
As soon as Richard became king (26 June 1483), Lovell was promoted to the office of Lord Chamberlain, and was made a Knight of the Garter, and given Wallingford Castle in 1485. Lovell helped in the suppression of Henry Stafford, 2nd Duke of Buckingham’s rebellion (1483), and as one of Richard’s most trusted ministers was gibbeted in Collingbourne’s couplet with William Catesby and Richard Ratcliffe:
(The 'dogge' here refers to a Lovell family heraldic symbol. Richard's symbol was a boar.)
Lovell had command of the fleet which was to have stopped Henry Tudor’s landing in 1485 but failed and then fought for Richard at the Battle of Bosworth Field (22 August 1485) and after the battle fled to sanctuary at Colchester. From there, he escaped the following year to organise a dangerous revolt in Yorkshire. When that failed he fled to Margaret of York in Flanders.
As a chief leader of the Yorkist party, Lovell took a prominent part in Lambert Simnel’s enterprise. With John de la Pole, Earl of Lincoln, he accompanied the pretender to Ireland and fought for him at the Battle of Stoke Field on 16 June 1487. He was seen escaping from the battle, but was never afterwards heard of; Francis Bacon relates that according to one report he lived long after in a cave or vault (History of Henry VII, p. 37, ed. Joseph Rawson Lumby). More than 200 years later, in 1708, the skeleton of a man was found in a secret chamber in the family mansion at Minster Lovell in Oxfordshire. It is supposed that Lovell had hidden himself there and died of starvation.