Richard de Redvers, 2nd Earl of Devon
Richard de Redvers, 2nd Earl of Devon( died 1162) was Earl of Devon from 1155 until his death and was feudal baron of Plympton in Devon.
He married Denise, one of the daughters and coheiresses of Reginald, Earl of Cornwall.
He was High Sheriff of Devon from 1154 – 1157.
He was the son of Baldwin de Redvers, 1st Earl of Devon and brother of William de Reviers, 5th Earl of Devon.
He was succeeded by his son Baldwin de Redvers, 3rd Earl of Devon( died 1188).
Isabel de Forz, suo jure 8th Countess of Devon
Isabel de Forz or Isabel de Redvers( July 1237 – 10 November 1293) was the eldest daughter of Baldwin de Redvers, 6th Earl of Devon( 1217 – 1245).
On the death of her brother Baldwin de Redvers, 7th Earl of Devon in 1262, without children, she inherited" suo jure"( in her own right) the earldom and also the feudal barony of Plympton in Devon, and the Lordship of the Isle of Wight.
After the early death of her husband and her brother, before she was thirty years old, she inherited their estates and became one of the richest women in England, living mainly in Carisbrooke Castle on the Isle of Wight, which she held from the king as tenant- in- chief.
She had six children, all of whom died before her.
On her death bed she was persuaded to sell the Isle of Wight to King Edward I, in a transaction that has ever since been considered questionable.
Her heir to the feudal barony of Plympton was her cousin Hugh de Courtenay( 1276 – 1340), feudal baron of Okehampton, Devon, who in 1335 was declared Earl of Devon.
Countess Wear, now a suburb of Exeter, is named after a weir that she built on the River Exe, and she is the subject of several legends and traditions.
Baldwin de Redvers, 1st Earl of Devon
Baldwin de Redvers, 1st Earl of Devon( died 4 June 1155), feudal baron of Plympton in Devon, was the son of Richard de Redvers and his wife Adeline Peverel.
He was one of the first to rebel against King Stephen, and was the only first rank magnate never to accept the new king.
He seized Exeter, and was a pirate out of Carisbrooke, but he was driven out of England to Anjou, where he joined the Empress Matilda.
She made him Earl of Devon after she established herself in England, probably in early 1141.
He founded several monasteries, notably those of Quarr Abbey( 1131), in the Isle of Wight, a priory at Breamore, Hampshire, and the Priory of St James, at Exeter.
Some monastic chronicles call his father also Earl of Devon, but no contemporary record uses the title, including the monastic charters.
Richard de Redvers, 4th Earl of Devon
Richard de Redvers, 4th Earl of Devon( died 1193) was Earl of Devon from 1188 until his death and was feudal baron of Plympton in Devon.
He inherited the title on the death of his elder brother Baldwin de Redvers, 3rd Earl of Devon, who died childless.
On his own death without issue the title passed to his uncle, William de Redvers, 5th Earl of Devon, third but only surviving son of the 1st Earl.
Baldwin de Redvers, 3rd Earl of Devon
Baldwin de Redvers, 3rd Earl of Devon( c. 1160–1188) was Earl of Devon from 1162 until his death and was feudal baron of Plympton in Devon.
His birth is not attested; but he had a younger brother, and he was invested with the Earldom between the Pipe Rolls of 1185 and 1186, so he should not have been much over twenty- one.
He married Denise the heiress of Raoul, Prince of Déols, lord of Châteauroux and Charenton- du- Cher.
After his death, she married André de Chauvigny.
He was succeeded by his brother, Richard de Redvers, 4th Earl of Devon.
William de Forz, 4th Earl of Albemarle
William de Forz, 4th Earl of Albemarle( died 1260)
( Latinised as" de Fortibus", sometimes spelt Deforce) played a conspicuous part in the reign of Henry III of England, notably in the Mad Parliament of 1258.
William married twice.
His first wife was Christina( died 1246), daughter and co-heiress of Alan, Lord of Galloway.
Her mother was one of the co-heiresses of the Earldom of Chester on the death of the last Earl in 1237.
He claimed that, as a Palatine, it could not be divided, and his wife should get it as the oldest co-heir.
He got the title, but the court decided that the lands should be divided, but this wife died in 1239 without issue.
However, he and his wife quitclaimed the earldom to Henry III in 1241 in exchange for modest lands elsewhere.
In 1241, on the death of his father, he inherited his lands, including honours associated with Cockermouth Castle in Cumberland, and Skipton Castle in Craven, Skipsea Castle in Holderness, both in Yorkshire.
He joined Henry III in campaigns in Poitou and Wales in 1242 and 1245, but not in Wales in 1257 because he was ill.
He held local offices in Cumberland, including justice of the forest for Cumberland in 1251, and sheriff of Cumberland in 1255 and keeper of Carlisle Castle, an office he held until his death.
Two years after the death of his first wife, he remarried in 1248 to Isabella de Redvers( 1237 – 1293), daughter of Baldwin de Redvers, 6th Earl of Devon and Lord of the Isle of Wight.
William de Forz died at Amiens in 1260.
His widow Isabella, on the death of her brother Baldwin de Redvers, 7th Earl of Devon in 1262, inherited his lands and called herself Countess of Devon and Aumale.
She had six children, all of whom pre-deceased her, including Thomas who died unmarried in 1269, and Avelina who married Edmund Crouchback, 1st Earl of Lancaster in 1269, but died childless in 1274 aged 15.
Amice de Clare
Amice de Clare (c. 1220 – 1284) was the daughter of Gilbert de Clare, 4th Earl of Hertford and Isabel Marshal.
She married, firstly, Baldwin de Redvers, 6th Earl of Devon, and secondly Robert de .
She founded Buckland Abbey.
Baldwin de Redvers, 6th Earl of Devon
Baldwin de Redvers, 6th Earl of Devon( 1217 – 15 February 1245), feudal baron of Plympton in Devon and Lord of the Isle of Wight, was the son of Baldwin de Redvers and Margaret FitzGerold and grandson of William de Redvers, 5th Earl of Devon.
Hugh de Courtenay, 1st/9th Earl of Devon
Hugh de Courtenay, 1st/ 9th Earl of Devon( 14 September 1276 – 23 December 1340) was the son of Sir Hugh de Courtenay( died 1292), feudal baron of Okehampton in Devon, by his wife Eleanor le Despenser( died 1328), sister of Hugh le Despenser, 1st Earl of Winchester.
Forty- one years after the death of Isabel de Redvers," suo jure" 8th Countess of Devon( died 1293)( eldest daughter of Baldwin de Redvers, 6th Earl of Devon), letters patent were granted by King Edward III of England, dated 22 February 1335, declaring him Earl of Devon, and stating that he' should assume such title and style as his ancestors, Earls of Devon, had wont to do so'.
This thus made him 1st Earl of Devon, if the letters patent are deemed to have created a new peerage, otherwise 9th Earl of Devon, if it is deemed a restitution of the old dignity of the de Redvers family, and he is deemed to have succeeded the" suo jure" 8th Countess of Devon, his second- cousin once removed.
Authorities differ in their opinions, and thus alternative ordinal numbers exist for this Courtenay earldom.
Baldwin de Redvers, 7th Earl of Devon
Baldwin de Redvers, 7th Earl of Devon (1 January 1236 – 1262), feudal baron of Plympton in Devon and Lord of the Isle of Wight, was the son of Baldwin de Redvers, 6th Earl of Devon and Amice de Clare, daughter of Gilbert de Clare, 5th Earl of Hertford.
He succeeded his father at the age of ten.
He died in the expedition of Henry III of England to France in 1262; the record of his death by the royal clerks was made on 13 September.
He was succeeded by his sister, Isabella de Fortibus, widow of William de Forz, 4th Earl of Albemarle.

Question: Who is Baldwin De Redvers, 7Th Earl Of Devon's maternal grandmother?
Answer: Isabel Marshal