The Term Marchio was applied in the Norman period to the Earl or Baron guarding the Welsh or Scottish Marches, or border territories. Similarly in Germany, the Count or Graf became known as the Markgraf, anglicized to Margrave. By the 12th century it had lost it's territorial significance. It was introduced to England by Richard II, brother-in-law of the Margrave of Brandenburg, the honour being conferred upon Robert de Vere, Earl of Oxford, who became Marquess of Dublin in 1385. The precedence between Dukes and Earls caused great offence to the Earls, and the patent was revoked in1386 in favor of the Dukedom of Ireland. The next recipient did not appreciate the degree. When John Beaufort, Marquess of Dorset, was attainted and the House of Commons appealed to Richard II for it's restoration, Beaufort begged the King not to restore this particular title "as the name of Marquess is a strange name in this realm."
The style of a marquess is Most Honourable. He is formally styled by the Sovereign, Our right trusty and entirely beloved cousin (and counselor when of the Privy Council).