Grey was the eldest son of Henry Gray, 1st Baron Grey of Codnor (died 1308) and Eleanor de Courteney. Richard succeeded to his fathers titles in 1308, upon Henry's death. Richard was one of the barons who at the assembly of Stamford on 6 August 1309, signed a letter of remonstrance to the pope on the abuses in the church. He was employed in the Scottish wars in 1311, fought during the English defeat of the Battle of Bannockburn in 1314, and again in 1319–20 during the unsuccessful siege of Berwick and other confrontations against the Scots in the Scottish Marches. During the baronial revolt against King Edward II of England, known as the Despenser War, he assisted Roger Mortimer and the Marcher Lords, who attacked and plundered the Welsh possessions of royal favourite Hugh le Despenser, the younger. For these attacks, Richard was pardoned by Parliament in August 1321. Together with John Giffard and Robert de Shirland, they testified to the claim of Bartholomew Badlesmere that Despenser, the younger was a traitor. Misled by false letters, the rebels attempted to place Gray, Giffard and Shirland firmly on their side, but from the end of 1321 Gray was firmly on the side of Edward II, who took action against the baronial opposition. Richard served with the royal army, which pursued the rebels under the command of Thomas of Lancaster to the north of England. Grey remained in the favour of the king, who visited him after the victory over Lancaster in March 1322 at Grey's castle at Codnor, Derbyshire.