Second child and eldest daughter of Joan of Acre and Gilbert 'the Red'. Eleanor married Hugh Despenser the Younger on 26 May 1306 when she was thirteen and a half, and their first child, Edward I's eldest great-grandchild Hugh the Even Younger, was born in 1308 or 1309. (Edward I, not, not, NOT Edward II as so many people continue to state, arranged Eleanor and Hugh's marriage.) Eleanor was extremely close to her uncle Edward II, who was only eight and a half years her senior. She and her two younger sisters were heirs to their brother's earldom of Gloucester.
Fourth and youngest child of Joan of Acre and Gilbert 'the Red', and only a few weeks old when her father died. Elizabeth was married three times and lived almost forty years as a widow, and was a remarkable woman who founded Clare College at Cambridge in 1338. Many of her household accounts are extant and demonstrate her kindness to her Despenser and Audley nieces and nephews, although events of the 1320s evidently fractured the relationship of the three de Clare sisters.
Eldest child of Joan of Acre and her second husband Ralph de Monthermer, and half-sister of the four de Clare siblings. Mary married Duncan MacDuff, earl of Fife, some time after 4 November 1307 when the pope granted a dispensation for them to marry. Duncan returned to his native Scotland in November 1314 after the battle of Bannockburn, and thereafter remained loyal to Robert Bruce, despite being Edward II's nephew-in-law. Countess Mary lived until well into her seventies. Her and Duncan's only child Isabella MacDuff was countess of Fife in her own right and married four times.
Joan was the second child of Joan of Acre and Ralph, and followed in the footsteps of her aunt Mary, Edward II's sister, by becoming a nun at Amesbury Priory. Unfortunately I know nothing about her at all, not even her approximate date of birth.
Third child of Joan and Ralph. Despite being Edward II's nephew, he played little role in the king's reign, and seemingly first became embroiled in politics when he joined the unsuccessful rebellion of his kinsman Henry, earl of Lancaster against Roger Mortimer and Isabella of France in late 1328. Thomas married a widow named Margaret Tyes; their only child Margaret was born in October 1329, and her son John Montacute became earl of Salisbury in 1397. Thomas de Monthermer was killed at the naval battle of Sluys in 1340.
Fourth child of Joan and Ralph, and the youngest of Joan of Acre's eight children. Given that he was a grandson and nephew of kings, Edward is oddly obscure. One of the few things I know about him is that in 1330 he joined the conspiracy of his uncle Edmund of Woodstock, earl of Kent (Edward I's youngest son) to restore Edward of Caernarfon to the throne. He appears to have been close to his half-sister Elizabeth de Clare, who arranged and paid for his funeral, and evidently he was living in her household when he died. Edward never married.
Only child of Edward II's third sister Margaret, born sometime in 1300 and succeeded his father John II as duke of Brabant in 1312. John married Marie d'Evreux, daughter of Philip IV of France's half-brother Louis, count of Evreux, whose younger sister Jeanne married their first cousin Charles IV of France as his third wife in 1324. Duke John had six legitimate children with Marie, and at least twenty illegitimate ones.
Oldest surviving son of Edward II's fifth sister Elizabeth and her second husband Humphrey de Bohun, earl of Hereford and Essex (she had no children with her first husband Count John I of Holland, who died at fifteen). John married the earl of Arundel's daughter Alice in 1325, but had no children, and died at the age of twenty-nine, to be succeeded by his brother Humphrey.
Second surviving son of Elizabeth and Humphrey, and succeeded his brother John as earl. Humphrey never married, and thus on his death his heir was his nephew, another Humphrey, son of Humphrey's younger brother William, below. It may be that both John and Humphrey de Bohun suffered from some kind of illness or disability.
Third surviving son of Elizabeth and Humphrey; he had a twin named Edward, who drowned in Scotland in 1334. William married Elizabeth Badlesmere, whose father Bartholomew was executed in 1322 by Edward II and who was the widow of Roger Mortimer's son and heir Edmund Mortimer. Edward III created his cousin earl of Northhampton in 1337. William and Elizabeth's son Humphrey (1341-1373) succeeded his father as earl of Northampton, and his uncle Humphrey as earl of Hereford and Essex. The younger Humphrey was also, via his mother, a half-brother of Roger Mortimer, second earl of March (1328-1360).
Oldest surviving child of Elizabeth and Humphrey, and married James le Botiler or Butler, earl of Ormond, and secondly Thomas Dagworth. Eleanor had five children with her two husbands.
Second surviving daughter of Elizabeth and Humphrey, and married Hugh Courtenay, future earl of Devon in 1325. They had numerous children, and both lived to a ripe old age: Margaret died at eighty, Hugh at almost seventy-four. There is a persistent story online that Margaret was married firstly to a distant cousin from Scotland called 'Sir Richard le Bon de Bohun' (?!) and had a son with him called John, but her family had the marriage annulled. This is pure fiction, an invention of centuries later without a shred of contemporary evidence to back any of it up.
Eldest child of Edward II's half-brother Thomas of Brotherton, earl of Norfolk, and his heir. The last survivor of all Edward I's grandchildren, and the first Englishwoman to be made a duchess in her own right. Her brother Edward died as a child, and her sister Alice was beaten to death by her husband in the early 1350s.
Joan was the third of the four children of Edward II's half-brother Edmund of Woodstock, earl of Kent, and Margaret Wake. Famous for being married to two men at the same time in the 1340s, William Montacute, earl of Salisbury and Thomas Holland, in 1360 she married her first cousin once removed, Edward III's eldest son Edward of Woodstock, prince of Wales. Joan gave birth to the future King Richard II in early 1367, in her late thirties. Of her siblings, her elder brother Edmund died as a child; her younger brother John died childless at the age of twenty-two; her elder sister Margaret died childless sometimes before 1352. Joan was thus the heir of her father, and of her maternal uncle Thomas, Lord Wake (died 1349). A fourteenth-century chronicler sarcastically called her 'the virgin of Kent', which makes me cackle with laughter. :-)