Reginald Grey, 3rd Baron Grey de Ruthyn (c. 1362 – 30 September 1440), a powerful Welsh marcher lord, succeeded to the title on the death of his father, Reginald Grey, 2nd Baron Grey de Ruthyn in July 1388. His mother was Eleanor Le Strange of Blackmere.
Grey married firstly, after 25 November 1378, Margaret de Roos (or Ros), daughter of Thomas de Ros, 4th Baron de Ros and Beatrice Stafford, daughter of Ralph de Stafford, 1st Earl of Stafford, by whom he had two sons and several daughters.
Grey married secondly on 7 February 1415, Joan de Astley, daughter of Sir William de Astley, 5th Baron Astley and Catherine de Willoughby, by whom he had three sons and three daughters.
His seizure of land belonging to Owain Glyndwr, and Henry IV's favoritism towards him sparked a wide-spread rebellion in Wales against English rule.
Grey was a member of the Council which governed England during the absence of Henry V in France in 1415; he later fought against the French in the Hundred Years War in 1420 and 1421. He had been previously a Governor of Ireland. Reginald Grey, 3rd Baron Grey de Ruthyn in Wikipedia