Aymer de Valence , 2nd Earl of Pembroke Aymer de Valence , 2nd Earl of Pembroke ( c . 1275 – 23 June 1324 ) was a Franco - English nobleman . Though primarily active in England , he also had strong connections with the French royal house . One of the wealthiest and most powerful men of his age , he was a central player in the conflicts between Edward II of England and his nobility , particularly Thomas , 2nd Earl of Lancaster . Pembroke was one of the Lords Ordainers appointed to restrict the power of Edward II and his favourite Piers Gaveston . His position changed with the great insult he suffered when Gaveston , as a prisoner in his custody whom he had sworn to protect , was removed and beheaded on the instigation of Lancaster . This led Pembroke into close and lifelong cooperation with the King . Later in life , however , political circumstances combined with financial difficulties would cause him problems , driving him away from the centre of power . Though earlier historians saw Pembroke as the head of a ' middle party ' , between the extremes of Lancaster and the king , the modern consensus is that he remained essentially loyal to Edward throughout most of his career . Pembroke was married twice , and left no legitimate issue , though he did have a bastard son . He is today remembered primarily through his wife ' s foundation of Pembroke College , Cambridge , and for his splendid tomb that can still be seen in Westminster Abbey . He was also an important figure in the wars against Robert the Bruce . Family and early years . Aymer was the son of William de Valence , son of Hugh X , Count of La Marche and Isabella of Angoulême . William was Henry III ' s half - brother through his mother ’ s prior marriage to King John , and as such gained a central position in the Kingdom of England . He had come to the earldom of Pembroke through his marriage to Joan de Munchensi , granddaughter of William Marshal . Aymer was the third son of his family , so little is known of his birth and early years . He is believed to have been born some time between 1270 and 1275 . As his father was on crusade with Lord Edward until January 1273 , a date towards the end of this period is more likely . With the death in battle in Wales of his remaining brother William in 1282 ( John , the elder brother , was dead in 1277 ) , Aymer found himself heir to the Earldom of Pembroke . William de Valence died in 1296 , and Aymer inherited his father ' s French lands , but had to wait until his mother died in 1307 to succeed to the Earldom . Through inheritance and marriages his lands consisted of – apart from the county palatine in Pembrokeshire – property spread out across England primarily in a strip from Gloucestershire to East Anglia , in south - east Ireland ( Wexford ) , and French lands in the Poitou - and Calais areas . In 1297 he accompanied Edward I on a campaign to Flanders , and seems to have been knighted by this time . With his French connections he was in the following years a valuable diplomat in France for the English King . He also served as military commander in Scotland . He won an important victory over Robert the Bruce in 1306 at the Battle of Methven , only to be defeated by Bruce at Loudoun Hill the next year . The Ordinances and Piers Gaveston . Edward I died in 1307 and was succeeded by his son Edward II . The new King at first enjoyed the good will of his nobility , Valence among them . Conflict soon ensued , however , connected especially with the enormous unpopularity of Edward ' s favourite Piers Gaveston . Gaveston ' s arrogance towards the peers , and his control over Edward , united the Baronage in opposition to the King . In 1311 the initiative known as the Ordinances was introduced , severely limiting Royal powers in financial matters and in the appointment of officers . Equally important , Gaveston was expelled from the realm - as Edward I had already done once before . Pembroke , who was not among the most radical of the Ordainers , and had earlier been sympathetic with the King , had now realised the necessity of exiling Gaveston . When Gaveston without permission returned from exile later the same year , a Baronial council entrusted Pembroke and The Earl of Surrey , with the task of taking him into custody . This they did on 19 May 1312 , but not long after Thomas of Lancaster , acting with the Earls of Warwick , Hereford and Arundel , seized Gaveston and executed him on 19 June . This criminal act had the effect of garnering support for the King , and marginalising the rebellious earls . As far as Pembroke is concerned , the seizing and execution of a prisoner in his custody was a breach of the most fundamental chivalric codes , and a serious affront to his honour . The event must therefore be seen as pivotal in turning his sympathies away from the rebels and towards the King . Later years . In the following years Pembroke worked closely with the King . He was appointed the King ’ s lieutenant in Scotland in 1314 , and was present at the disastrous English defeat at the Battle of Bannockburn , where he helped lead Edward away from the field of battle . In 1317 , however , while returning from a papal embassy to Avignon , he was captured by a Jean de Lamouilly , and held for ransom in Germany . The ransom of £10 , 400 was to cause Pembroke significant financial difficulties for the remainder of his life . Although ostracised because of the murder of Gaveston , Thomas of Lancaster had regained virtual control of royal government in the period after Bannockburn . Proving himself as incapable to rule as Edward , however , he soon grew unpopular . Pembroke was one of the magnates who in the years 1316 - 18 tried to prevent civil war from breaking out between the supporters of Edward and those of Lancaster , and he helped negotiate the Treaty of Leake in 1318 , restoring Edward to power . Peace did not last long , however , as the King by now had taken on Hugh Despenser the younger as another favourite , in much the same position as Gaveston . Pembroke ' s attempts at reconciliation eventually failed , and civil war broke out in 1321 . In 1322 Lancaster was defeated at the Battle of Boroughbridge , and executed . Pembroke was among the Earls behind the conviction . After Boroughbridge Pembroke found himself in a difficult situation . The opponents of Hugh Despenser and his father had lost all faith in him , but at the same time he found himself marginalised at court where the Despensers ' power grew more and more complete . On top of this came his financial problems . On 24 June 1324 , while on an embassy to France , he suddenly collapsed and died while lodging somewhere in Picardy . Legacy . T . F . Tout , in 1914 one of the first historians to make a thorough academic study of the period , considered Pembroke the one favourable exception in an age of small - minded and incompetent leaders . Tout wrote of a ' middle party ' , led by Pembroke , representing a moderate position between the extremes of Edward and Lancaster . This ' middle party ' supposedly took control of royal government through the Treaty of Leake in 1318 . In his authoritative study of 1972 , J . R . S . Phillips rejects this view . In spite of misgivings with the King ’ s favourites , Pembroke was consistently loyal to Edward . What was accomplished in 1318 was not the takeover by a ' middle party ' , but simply a restoration of royal power . Aymer married twice ; his first marriage , before 1295 , was to Beatrice , daughter of Raoul de Clermont , Lord of Nesle in Picardy and Constable of France . Beatrice died in 1320 , and in 1321 he married Marie de St Pol , daughter of Gui de Châtillon , Count of St Pol and Butler of France . He never had any legitimate children , but he had an illegitimate son , Henry de Valence , whose mother is unknown . Pembroke ' s most lasting legacy is probably through his second wife , who in 1347 founded Pembroke College , Cambridge . The family arms are still represented on the dexter side of the college arms . Aymer de Valence was buried in Westminster Abbey , where his tomb can still be seen as a splendid example of late gothic architecture , elaborating on the design of the nearby tomb of Edmund Crouchback .