[3] He is mentioned in the Annales Rerum Gestarum Angliae et Hiberniae Regnate Elizabetha by William Camden, in the entry for year 1573: "18.
His great-uncle Richard Grey, 3rd Earl of Kent had wound up heavily in debt, probably through gambling, and was forced to alienate most of his property.
Henry Grey had inherited the claim to the title but little property and lived mostly as a gentleman, a private citizen.
Reginald lived the same way until Elizabeth I restored to him his title and part of his property in 1572 following a campaign suported by his mother in law Katherine Brandon, Duchess of Suffolk.
[3] His younger brothers Henry and Charles successively inherited the Kent title following his death on 17 March 1573.