Aubrey de Vere, 10th Earl of Oxford
Aubrey de Vere, 10th Earl of Oxford( c. 1338 – 15 February 1400) was the third son of John de Vere, 7th Earl of Oxford and Maud de Badlesmere, daughter of Bartholomew de Badlesmere, 1st Lord Badlesmere.
Aubrey de Vere had three brothers, John, Thomas, and Robert, and three sisters.
Margaret, Maud and Elizabeth.
His eldest brother, John, married the daughter of Hugh Courtenay, Earl of Devon, but died in 1350 in his father's lifetime.
Another brother, Robert, also died in his father's lifetime.
Aubrey de Vere's third brother, Thomas, succeeded his father as 8th Earl of Oxford, and was in turn succeeded by his only son, Robert de Vere, 9th Earl of Oxford, who died in 1392 without issue, leaving Aubrey de Vere to inherit the earldom.
In 1360 Aubrey de Vere was made steward of the royal forest of Havering in Essex.
In 1367 was retained to' abide for life' with the Black Prince, with a substantial allowance.
He was knighted, made constable of Wallingford Castle in 1375 and also given the honours of Wallingford and St. Valery, though he gave up Wallingford in 1378 for Hadleigh Castle.
Edward III used him as an ambassador in seeking peace with France.
In 1381, de Vere became a Chamberlain of the Royal Household and member of the privy council.
In 1388 his nephew, Robert de Vere, Duke of Ireland and 9th Earl of Oxford was deemed a traitor, causing Aubrey to lose his post of chamberlain.
However, after Robert ’s death in 1392, the king gave Aubrey the title of Earl of Oxford allowing him to take a seat in parliament.
Aubrey ’s son, Richard became the 11th Earl of Oxford on his death.
An administrator of Aubrey de Veer appears as William Tasburgh, of Raylegh, parson, in 1401.
Robert de Vere, 5th Earl of Oxford
Robert de Vere, 5th Earl of Oxford (c. 1220 – 1296) was the son and heir of Hugh de Vere, 4th Earl of Oxford, and chamberlain to Queen Eleanor.
Elizabeth Trentham, Countess of Oxford
Elizabeth de Vere, Countess of Oxford, formerly Elizabeth Trentham( d. c. December 1612), was the second wife of the Elizabethan courtier and poet Edward de Vere, 17th Earl of Oxford.
Robert de Vere, 6th Earl of Oxford
Robert de Vere, 6th Earl of Oxford( c. 24 June 1257 – 17 April 1331) was the son and heir of Robert de Vere, 5th Earl of Oxford, by his wife Alice de Sanford.
Robert the younger took part in several of the military campaigns of Edward I, Edward II and Edward III in Wales, Scotland and France.
His coat of arms appears in the 1298 Falkirk Roll at the Battle of Falkirk.
He was married to Margaret Mortimer, daughter of Roger Mortimer, 1st Baron Wigmore.
He also officiated at the Coronation of Queen Isabella, wife of Edward II, in 1308.
His only son Thomas died before him, and when Robert died in 1331, he was succeeded by his nephew John de Vere, 7th Earl of Oxford.
He had a daughter, Ellen, who married Sir Hugo de Naunton.
Richard de Vere, 11th Earl of Oxford
Richard de Vere, 11th Earl of Oxford( 15 August 1385 – 15 February 1417) was the son and heir of Aubrey de Vere, 10th Earl of Oxford.
He took part in the trial of Richard, Earl of Cambridge and Lord Scrope for their part in the Southampton Plot, and was one of the commanders at Agincourt in 1415.
Hugh de Vere, 4th Earl of Oxford
Hugh de Vere, 4th Earl of Oxford (c. 1207 – December 1263) was the only son and heir of Robert de Vere, 3rd Earl of Oxford and Isabel de Bolebec, daughter and eventual sole heiress of Hugh de Bolebec.
John de Vere, 7th Earl of Oxford
John de Vere, 7th Earl of Oxford( c. 12 March 1312 – 24 January 1360) was the nephew and heir of Robert de Vere, 6th Earl of Oxford who succeeded as Earl of Oxford in 1331, after his uncle died without issue.
John de Vere was a trusted captain of Edward III in the king's wars in Scotland and France, and took part in both the Battle of Crécy and the Battle of Poitiers.
He died campaigning in France in 1360.
Throughout his career he was closely associated with William de Bohun, 1st Earl of Northampton, who was his brother- in- law.
Robert de Vere, 19th Earl of Oxford
Robert de Vere, 19th Earl of Oxford (b. after 23 August 1575 – 7 August 1632) was a British soldier, and the penultimate Earl of Oxford.
Margery Golding
Margery Golding, Countess of Oxford( c. 1526 – 2 December 1568) was the second wife of John de Vere, 16th Earl of Oxford, the mother of Edward de Vere, 17th Earl of Oxford, and the half- sister of Arthur Golding, the English translator.
Robert de Vere, 3rd Earl of Oxford
Robert de Vere( after c. 1165 – before 25 October 1221), hereditary Master Chamberlain of England, was son of Aubrey de Vere, 1st Earl of Oxford, and Agnes of Essex.
He succeeded his brother as the third Earl of Oxford, and was one of the twenty- five guarantors of Magna Carta.
Robert de Vere was the second surviving son of Aubrey de Vere, 1st Earl of Oxford, and his third wife, Agnes of Essex.
The date of his birth is not known, but he was likely born after 1164.
Almost nothing is known of his life until 1207, when he married Isabel de Bolebec, the widow of Henry de Nonant( d.1206) of Totnes, Devon.
In 1206- 7 Isabel and her sister Constance were co-heiresses of their niece, another Isabel de Bolebec, the countess of Oxford by her marriage to Robert's brother, Aubrey de Vere, 2nd Earl of Oxford.
They divided the barony of Whitchurch.
The fact that aunt and niece had identical names, Isabel de Bolbec, and were successively countesses of Oxford and heiresses of Whitchurch has led to confusion between the two women.
When Robert's brother, Aubrey de Vere, 2nd Earl of Oxford, died in the latter half of 1214, Robert succeeded to his title and estates and the hereditary office of Master Chamberlain of England.
The dower of Earl Aubrey's second wife, Alice( possibly his cousin, a daughter of Roger Bigod, 2nd Earl of Norfolk), had not been formalized.
In 1215 Oxford settled his sister- in- law's dower by lot, the earl drawing two knights' fees for every one drawn by Alice.
This is the only known instance of dower being settled in this manner.
Oxford joined the disaffected barons who met at Stamford and forced King John to issue Magna Carta at Runnymede on 15 June 1215.
The earl was elected one of the barons who were to guarantee the King's adherence to its terms.
Together with other Magna Carta barons, he was excommunicated as a rebel by Pope Innocent III on 16 December 1215, and joined them in offering the crown to Prince Louis of France.
Oxford took up arms against King John, but pledged loyalty to him after the King had taken Castle Hedingham in March 1216.
Later in the same year, however, he did homage to Prince Louis at Rochester.
Louis entered London and was proclaimed King.
On 14 June 1216, he captured Winchester and soon controlled over half of England.
In the midst of this crisis, King John died, prompting many of the barons to desert Louis in favor of John's nine- year- old son, Henry III.
In 1217 Prince Louis retook Castle Hedingham and restored it to Oxford, but despite this Oxford transferred his allegiance to the new King in October 1217.
Although he did homage to Henry, he was not fully restored in his offices and lands until February 1218.
Earl Robert served as a king's justice in 1220- 21, and died shortly before 25 October 1221.
He was buried at Hatfield Regis Priory, where either his son, Hugh de Vere, 4th Earl of Oxford, or his grandson, Robert de Vere, 5th Earl of Oxford had an effigy erected in which he is depicted in chain mail, cross- legged, pulling his sword from its scabbard and holding a shield displaying his de Vere arms.

Question: Who is the paternal grandfather of Robert De Vere, 5Th Earl Of Oxford?