CLIFFORD, the name of a famous English family and barony, taken from the village of Clifford in Herefordshire, although the family were mainly associated with the north of England.
Robert de Clifford (c. 1275-1314), a son of Roger de Clifford (d. 1282), inherited the estates of his grandfather, Roger de Clifford, in 1286; then he obtained through his mother part of the extensive land of the Viponts, and thus became one of the most powerful barons of his age. A prominent soldier during the reigns of Edward I. and Edward II., Clifford was summoned to parliament as a baron in 1299, won great renown at the siege of Carlaverock Castle in 1300, and after taking part in the movement against Edward II.'s favourite, Piers Gaveston, was killed at Bannockburn. His son Roger, the 2nd baron (1299-1322), shared in the rebellion of Thomas, earl of Lancaster, and was probably executed at York on the 23rd of March 1322. Robert's grandson Roger, the 5th baron (1333-1389), and the latter's son Thomas, the 6th baron (c. 1363-c. 1391), served the English kings on the Scottish borders and elsewhere. The same is true of Thomas, the 8th baron (1414-1455), who was killed at the first battle of St Albans in May 1455.
Thomas's son John, the 9th baron (c. 1435-1461), was more famous. During the Wars of the Roses he fought for Henry VI., earning by his cruelties the name of the "butcher"; after the battle of Wakefield in 1460 he murdered Edmund, earl of Rutland, son of Richard, duke of York, exclaiming, according to the chronicler Edward Hall, "By God's blood thy father slew mine; and so will I do thee and all thy kin." Shakespeare refers to this incident in King Henry VI., and also represents Clifford as taking part in the murder of York. It is, however, practically certain that York was slain during the battle, and not afterwards like his son. Clifford was killed at Ferrybridge on the 28th of March 1461, and was afterwards attainted. His young son Henry, the 10th baron (c. 1454-1523), lived disguised as a shepherd for some years, hence he is sometimes called the "shepherd lord." On the accession of Henry VII. the attainder was reversed and he received his father's estates. He spent a large part of his time at Barden in Lancashire, being interested in astronomy and astrology. Occasionally, however, he visited London, and he fought at the battle of Flodden in 1513. This lord, who died on the 23rd of April 1523, is celebrated by Wordsworth in the poems "The white doe of Rylstone" and "Song at the feast of Brougham Castle." Henry, the 11th baron, was created earl of Cumberland in 1525, and from this time until the extinction of the title in 1643 the main line of the Cliffords was associated with the earldom of Cumberland (q.v.).
Richard Clifford, bishop of Worcester and London under Henry IV. and Henry V., was probably a member of this family. This prelate, who was very active at the council of Constance, died on the 20th of August 1421.
On the death of George, 3rd earl of Cumberland, in 1605, the barony of Clifford, separated from the earldom, was claimed by his daughter Anne, countess of Dorset, Pembroke and Montgomery; and in 1628 a new barony of Clifford was created in favour of Henry, afterwards 5th and last earl of Cumberland. After Anne's death in 1676 the claim to the older barony passed to her daughter Margaret (d. 1676), wife of John Tufton, 2nd earl of Thanet, and her descendants, whose title was definitely recognized in 1691. After the Tuftons the barony was held with intervening abeyances by the Southwells and the Russells, and to this latter family the present Lord De Clifford belongs. 
When the last earl of Cumberland died in 1643 the newer barony of Clifford passed to his daughter Elizabeth, wife of Richard Boyle, 2nd earl of Cork, and from the Boyles it passed to the Cavendishes, falling into abeyance on the death of William Cavendish, 6th duke of Devonshire, in 1858.
The barony of Clifford of Lanesborough was held by the Boyles from 1644 to 1753, and the Devonshire branch of the family still holds the barony of Clifford of Chudleigh, which was created in 1672.
See G. E. Cockayne), Complete Peerage (1887-1898); and T. D. Whitaker, History of Craven (1877).
 The original writ of summons (1299) was addressed in Latin, Roberto domino de Clifford, i.e. Robert, lord of Clifford, and subsequently the barons styled themselves indifferently Lords Clifford or de Clifford, until in 1777 the 11th lord definitively adopted the latter form. The "De" henceforth became part of the name, having quite lost its earliest significance, and with unconscious tautology the barony is commonly referred to as that of De Clifford.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)