This is the second part of my post (part one) about Edward II's cousin Marie de St Pol, who married Aymer de Valence, earl of Pembroke, in July 1321. Practically nothing is known of their married life together, which lasted slightly less than three years: Aymer died suddenly on his way to Paris on 23 June 1324, sent by Edward II to negotiate with Charles IV regarding the latest outbreak of hostilities between England and France over Gascony. Edward, in Kent, heard the news of Aymer's death a mere three days later, and sent his confessor Robert Duffield to Marie to break the news; she heard on the 27th.  Aymer, who was in his late forties or early fifties - Marie was about twenty - collapsed and died unshriven in his servants' arms, although the Brut chronicle includes a scurrilous story that Aymer was murdered while sitting on the toilet. This, thought the chronicler - as pro-Lancastrian as ever - was God's vengeance, as Pembroke had been one of the men to condemn 'Saint' Thomas of Lancaster to death and never repented of "that wicked deed."  Aymer de Valence was buried in Westminster Abbey on 1 August, where his tomb can still be seen; although it was Edward II's own decision to bury his kinsman in the abbey, the king was still in Kent at the time and did not attend the funeral.
As I've pointed out before, Edward II's treatment of the wives and children of his enemies in the 1320s was despicable, and Marie, although her late husband had long been a supporter of the king, suffered because Aymer had not supported the Despensers and had begged the king to exile them in 1321. Marie was later to claim - albeit surely with some exaggeration - that Edward II seized over £20,000 worth of her late husband's possessions and kept them in his own hands in return for a pardon of royal debts to Aymer. She also had to sell all her late husband's livestock to Hugh Despenser the Younger for 1000 marks, a sum certainly far below their true value, in order to pay for her husband's funeral, and was also forced to relinquish certain wardships and lands to Despenser. Fifty-three years later, Marie had still not paid off all Aymer's debts. 
In August 1324, Edward II went to war with his brother-in-law Charles IV of France, and in November that year granted protection for two years to Marie and several members of her household, as they were "of the power of the king of France" and thus enemy aliens.  Various modern writers claim that Marie de St Pol was a close friend of Queen Isabella and that this was probably a reason for the Despensers' hostility towards the dowager countess , although I'm not sure what evidence this statement is based on; Isabella and Marie were, at least, connected by marriage, as Marie's eldest sister was the third wife of Isabella's uncle Charles de Valois. Although some secondary sources state that Marie accompanied Isabella on her trip to France from March 1325 to September 1326, Marie in fact was not named as one of Isabella's attendants at the time of her departure, only appointed attorneys to act for her in England while she travelled overseas on 12 December 1325 (by which point Edward II knew that Isabella had refused to return to him so would not have permitted Marie to join her in France), was in England in August 1325 and June 1326, and was exempted from the order to arrest French people in England that summer.  There is considerably more evidence of Marie's close friendship with Edward II's niece Elizabeth de Clare, eight or nine years her senior, with whom Marie remained in frequent contact until Elizabeth's death in 1360.  Marie may well have been inspired by her friend's foundation of Clare College, Cambridge in 1338 (Elizabeth in turn was following in the footsteps of her Uncle Edward), and in 1347 founded Pembroke College, originally known as Valence Marie Hall, at Cambridge.
Marie, whether a close friend of Queen Isabella or not, was, given the Despensers' shabby treatment of her which took place with Edward II's knowledge and consent, presumably very glad to see their downfall in 1326/27, and her uncle John of Brittany, earl of Richmond - first cousin of Edward II and second cousin of Isabella - supported the queen and Roger Mortimer. On 3 September 1327, Mortimer, the latest royal favourite and ruler of England, requested a grant of Marie's marriage to his second son, Roger. Given that the elder Roger was not yet earl of March, this was hardly a great match for a dowager countess, and in fact the marriage was destined never to take place, as the younger Roger died sometime before 27 August 1328.  Marie de St Pol, countess of Pembroke, would live for a staggering fifty-three years as a widow, and died on 16 March 1377 in her early seventies, failing by just three months to live into the reign of Edward II's great-grandson Richard II. Of her contemporaries, probably only Edward II's niece Margaret de Bohun, countess of Devon (1311-1391) and Blanche of Lancaster, Lady Wake (c. 1302-1380) lived to be older. Marie made her will three days before her death, bequeathed a gold cross to Westminster Abbey where her late husband was buried, and asked to be laid to rest at Denny Abbey in Cambridgeshire.
1) J.R.S. Phillips, Aymer de Valence, Earl of Pembroke 1307-1324: Baronial Politics in the Reign of Edward II, p. 233.
2) The Brut or Chronicles of England, ed. F.W.D. Brie, vol. 1, p. 232.
3) Phillips, Valence, pp. 235-237; Calendar of Patent Rolls 1324-1327, p. 165; The National Archives SC 8/66/3266.
4) Cal Pat Rolls 1324-1327, p. 57.
5) Natalie Fryde, The Tyranny and Fall of Edward II 1321-1326, p. 113; Alison Weir, Isabella, She-Wolf of France, Queen of England, pp. 131, 143; Frances A. Underhill, For Her Good Estate: The Life of Elizabeth de Burgh, p. 38.
6) Cal Pat Rolls 1324-1327, pp. 200, 275; Calendar of Close Rolls 1323-1327, pp. 412, 505, 557.
7) Underhill, Good Estate, pp. 103-107.
8) Cal Pat Rolls 1327-1330, p. 166; Ian Mortimer, The Greatest Traitor: The Life of Sir Roger Mortimer, pp. 201, 320.