The title Earl of Rutland was created on 25 February 1390 for Edward of Norwich (1373–1415), son of Edmund of Langley, 1st Duke of York, and grandson of King Edward III. Upon the Duke's death in 1402 Edward became Duke of York. The title Earl of Rutland fell into disuse upon his death at the Battle of Agincourt, and was assumed by other members of the House of York including the first earl's nephew Richard Plantagenet, 3rd Duke of York, the father of King Edward IV.
Thomas Manners (c. 1488–1543), son of the 11th Baron de Ros of Hamlake, Truibut and Belvoir, was created Earl of Rutland in the Peerage of England in 1525. He was the great-grandson of Richard Plantagenet. The barony of 'de Ros of Hamlake, Truibut and Belvoir' (sometimes spelled Ros, Roos or de Roos) was created by Simon de Montfort with a writ of summons to the House of Lords for Robert de Ros (1223–1285) in 1264. The title may pass through the female line when there is no male heir, and accordingly, when the 3rd Earl, Edward Manners (c. 1548–1587), left no sons, the barony of Ros passed to the family of his daughter Elizabeth (d. 1591) who became the wife of the 2nd Earl of Exeter. The 3rd Earl was succeeded as 4th Earl by his brother John (d. 1588). The barony of Ros was restored to the Manners family when Francis Manners, the 6th Earl (1578–1632), inherited it in 1618 from his cousin William Cecil (1590–1618). However, Francis died without male issue and the assumption of the courtesy title of Lord Ros for the eldest son of subsequent earls appears to have had no legal basis. On the death of the seventh Earl in 1641 the Earldom passed to his distant cousin John Manners of Haddon Hall, grandson of the second son of the first Earl.
The most notable Marquess of Granby was John Manners (1721–1770), eldest son of the third Duke. He was an accomplished soldier and highly popular figure of his time; in 1745 he became a colonel; his military career flourished during the Seven Years' War.