Despenser War The Despenser War ( 1321 – 22 ) was a baronial revolt against Edward II of England led by the Marcher Lords Roger Mortimer and Humphrey de Bohun . The rebellion was fuelled by opposition to Hugh Despenser the Younger , the royal favourite . After the rebels ' summer campaign of 1321 , Edward was able to take advantage of a temporary peace to rally more support and a successful winter campaign in southern Wales , culminating in royal victory at the battle of Boroughbridge in the north of England in March 1322 . Edward ' s response to victory was his increasingly harsh rule until his fall from power in 1326 . Causes of the war . The initial success of the rebels reflected the power of the Marcher Lords . Since Edward I ' s conquest of Wales , " [ t ] he marcher privileges remained undiminished , and the marcher energies which could no longer find employment in the struggle against the Welsh , sought new direction in the fertile field of English politics . " The death of the last Earl of Gloucester also meant the redistribution of his vast estates and lordships in Ireland and Wales . The important Lordship of Glamorgan passed to the late earl ' s brother - in - law , the younger Despenser , married to his eldest sister Eleanor . The Lords Ordainers , the powerful baronial hegemony led by the Earl of Lancaster , despised the younger Despenser and the his father , the elder Depsenser , on account of the influence they both wielded over the king . The council of Ordainers was formed in 1311 to reform the King ' s household , restrict his royal prerogatives , supervise the economy , and they insisted on the banishment of his then favourite , Piers Gaveston , husband of the earl of Gloucester ' s sister Margaret . Roger Mortimer , his uncle , Roger Mortimer de Chirk , and Humphrey de Bohun , a staunch Ordainer , were avowed enemies of the Despensers . The younger Despenser , through his marriage with Eleanor , received many expensive gifts , and much property and land grants in the Marches . The passage of Glamorgan to Despenser in its entirety angered his brothers - in - law , Roger d ' Amory and Hugh de Audley , who were cheated out of their share of lands which rightfully belonged to them . Hostility deepened among the Marcher Lords when Despenser titled himself " Lord of Glamorgan " and " Earl of Gloucester " . First phase : February – August 1321 . In February 1321 Mortimer , Hereford and Lancaster agreed on an attack on the Despenser lands in Wales . Edward responded in March by mobilising his forces in Wales , demonstrating that he intended to make any attack on the Despensers an attack on the crown , and therefore treasonable . The king travelled to Gloucester and called upon the Marcher Lords to join him there ; Mortimer and Hereford declined . Mobilising more forces , Edward marched on to Bristol , and repeated his call for the Marcher Lords to convene with him there in May . They again declined . Mortimer and Hereford promptly began their attack on the Despenser lands . Newport , Cardiff and Caerphilly were seized by Mortimer in an intense eight - day campaign . Mortimer and Hereford then set about pillaging Glamorgan and Gloucestershire , before marching north to join Lancaster at Pontefract . The barons then swore an alliance at Sherburn - in - Elmet in June , naming their faction the " contrariants " and promising to remove the Despensers for good . Edward had returned to London , where he held his own parliament to discuss courses of action . Mortimer led his army east towards London as well , reaching St Albans in late July . The city of London refused to let Mortimer ' s forces in , and his forces placed the capital under effective siege . Lancaster arrived in August to support him and a tense stand - off ensued , with the younger Despenser threatening the rebels from a ship on the River Thames , and the barons threatening to begin to destroy royal properties and lands outside London unless he desisted . The Earl of Pembroke , a moderate baron with strong French links , intervened in an attempt to defuse the crisis . Edward continued to refuse to negotiate or exile the Despensers , so Pembroke arranged for Queen Isabella to publicly go down on her knees to appeal to Edward to exile the Despensers . This provided him with a face - saving excuse to exile the Despensers and defuse the crisis , but it was clear Edward intended to arrange their return at the first opportunity . Second phase : October 1321 - March 1322 . Despite the momentary respite , by the autumn of 1321 the tensions between Edward and the baronial opposition led by Thomas of Lancaster , were extremely high , with both sides retaining mobilised forces across the country . At this point , Isabella undertook a pilgrimage to Canterbury , during which she left the traditional route to stop at Leeds Castle , a fortification held by Bartholomew de Badlesmere , steward of the King ' s household who had by 1321 joined the ranks of Edward ' s opponents . Historians believe that the pilgrimage was a deliberate act by Isabella on Edward ' s behalf to create a " casus belli " . Lord Badlesmere was away at the time , having left his wife Margaret in charge of the castle . When the latter adamantly refused the Queen admittance , fighting broke out outside the castle between Isabella ' s guards and the garrison . Edward mobilised his own faction and placed Leeds castle under siege , giving Isabella the Great Seal and control of the royal Chancery . The attack on Isabella increased Edward ' s popular support ; the moderate barons moved to support him , as did many volunteers from London . Before long , chroniclers record that Edward had an army of 30 , 000 men besieging Leeds castle , although this may represent an overestimate . The castle surrendered at the end of October and Edward took a vicious revenge on the constable and his men . Edward ' s position was now much stronger than in August and he set about revoking the banishment order on the Despensers . Mortimer and Hereford travelled north to discuss the situation with Lancaster , and the three reaffirmed their intent to oppose Edward . Back in the Welsh borders , however , there was an uprising of the local peasantry , and Mortimer and Hereford were forced to return south to deal with the problem . Edward marched to Cirencester in December , preparing to invade the Welsh borders . In the north , Lancaster was attempting to enlist the support of the Scots in a bid to bring more forces to bear before Edward could retake south Wales . In January 1322 Edward finally overcame the resistance along the River Severn and advanced into the Welsh Marches ; the situation was now impossible and Roger Mortimer and his uncle , Roger Mortimer de Chirk surrendered to the King at Shrewsbury on 22 January 1322 . Edward turned north , assisted by the Despensers who had secretly returned from exile in mid - January . Edward mustered his men at Coventry in February , crossed the River Trent after the Battle of Burton Bridge , and engaged Lancaster and his forces at the Battle of Boroughbridge on 16 March . Edward was victorious . Captured after the battle , Lancaster was promptly executed , leaving Edward and the Despensers firmly in control of England and the Welsh Marches . Aftermath of the Despenser War . The Despenser War " totally changed the political scene in England " . Edward ' s victory provided the catalyst for the disintegration of the baronial oligarchy giving the King the opportunity to resume the regal powers the Ordainers had denied him since they presented their Ordinances to him in 1311 . Roger Mortimer was imprisoned in the Tower of London after his surrender at Shrewsbury . In August 1323 he escaped to France where he later joined Queen Isabella , who was ostensibly on a peace mission , but was actually seeking assistance from her brother , King Charles IV of France to oust the Despensers . Mortimer and Isabella obtained the necessary help in Flanders and in 1326 the successful Invasion of England was launched . This invasion led to the executions of the two Despensers , the deposition and killing of Edward II , and the seizure of authority by Queen Isabella and Roger Mortimer , who became the " de facto " rulers of England from 1327 to 1330 . Mortimer was hanged , drawn and quartered in November 1330 by the order of Isabella ' s son King Edward III after he ousted his mother and Mortimer from power and assumed personal rule .