I wrote in the last post about the eventful parliament of January/February 1316, and more problems beset Edward II when he heard news of an uprising which had recently begun in South Wales. The earl of Gloucester killed at Bannockburn had been lord of Glamorgan, which was destined to pass to his brother-in-law Hugh Despenser the Younger, but while Gloucester's widow was claiming (for many, many months!) to be pregnant with the earl's heir, the lordship remained in the king's hands and Edward II appointed royal administrators to rule it on his behalf. One of them was Sir Payn Turberville or Turville, appointed custodian of Glamorgan in July 1315 and hated there for his arrogance and tyranny. The unfortunate inhabitants, starving during the Great Famine, beaten and extorted of money by Turberville, suffered terribly. Llywelyn Bren, lord of Senghenydd and Meisgyn, decided he had had enough. The earl of Gloucester had thought highly of Llywelyn and granted him high office, but Payn Turberville removed his authority and treated him with contempt, which led a furious Llywelyn to tell a room full of his supporters that "The day will come when I will put an end to the insolence of Payn and give him as good as he gives me." 
Turberville promptly denounced him to Edward II for sedition, and the king summoned Llywelyn to court to explain himself. Llywelyn went cautiously, not sure of the reception he would get from the unpredictable Edward, intending to gloss over his insults to Turberville if he possibly could and, more importantly, to inform the king of his Welsh subjects' suffering. Unfortunately, Llywelyn's worst fears came true. Mishandling the situation as completely as only he could have, Edward II refused to meet Llywelyn and promised him that if he had truly uttered such things against a royal official, he would be hanged. He ordered Llywelyn to appear at the Lincoln parliament to defend his actions.
Llywelyn had no intention of going to Lincoln when it would probably result in his swinging at the end of a rope, and instead prepared for war. On 26 January 1316 - the day before Edward II arrived in Lincoln to open parliament - Llywelyn attacked the great stronghold of Caerphilly, built by the earl of Gloucester's father Gilbert 'the Red' in the 1270s. Although he could not penetrate the inner ward of the impregnable castle, he burnt the outer ward, taking the custodian captive, killing some servants and wounding others. The revolt spread throughout Glamorgan. Llywelyn and his many supporters – said to number 10,000 – carried off Payn Turberville's goods into the mountains where they were hiding, and Llywelyn threatened to kill the hated official. The news took a few days to travel the more than 200 miles from Caerphilly to Lincoln, and when Edward II finally heard on 7 February, he immediately sent men to capture Llywelyn and nip his rebellion in the bud, exclaiming "Go quickly, and pursue this traitor, lest from delay worse befall us and all Wales rise against us."
Among the men the king chose to campaign against Llywelyn and arrest him for his "diverse homicides, depredations, arsons and other offences" were:
- Humphrey de Bohun, earl of Hereford, Edward's brother-in-law, killed at the battle of Boroughbridge in 1322
- Roger Mortimer, yes, that Roger Mortimer, then in his late twenties and loyal to the king
- Roger Mortimer of Chirk, his uncle
- Bartholomew Badlesmere, steward of Edward II's household from 1318 to 1321 and executed in 1322
- Oliver Ingham, future seneschal of Gascony, arrested with Roger Mortimer in October 1330 by Edward III
- John Giffard of Brimpsfield, executed in York in 1322
- the earl of Lancaster's brother Henry, Edward II's first cousin
- Rhys ap Gruffydd of South Wales, one of Edward's staunchest supporters, even after his deposition (see below)
- Edward II's current court favourites Roger Damory, Hugh Audley and William Montacute, the latter the father of Edward III's close friend William Montacute, earl of Salisbury.  Montacute wrote to inform Edward on 11 March 1316 that "the bailiff of Gloucester has served you falsely" and that instead of sending a hundred good footmen to the campaign against Llywelyn had sent only forty-eight "worthless rascals" (raskaille de nyent), and that Montacute had therefore handed the bailiff over to the sheriff of Gloucestershire "till your will be known."  I don't know what happened to him.
It's interesting to note that Edward II didn't send his nephew-in-law Hugh Despenser the Younger to join the attack on Llywelyn, although Despenser was set to become lord of Glamorgan by right of his wife Eleanor - either because Edward didn't trust him then, because he didn't think Despenser was up to the task militarily, because he was angry with him for demanding his wife's inheritance numerous times before parliament and the king's council, attacking John Ros during the Lincoln parliament and seizing Tonbridge Castle a few months before - whether for all or none of these reasons, I don't know.
Llywelyn Bren was quickly overcome by this overwhelming demonstration of royal power and fled to Ystradfellte in the Brecon Beacons. He told his men that he would hand himself over to the English, because "it is better that one man should die than the whole race should be exiled or perish by the sword," and submitted to the earl of Hereford, who sent him to Edward. Hereford and the Mortimers were impressed with Llywelyn's bearing and courage and asked the king to show him leniency, though one suspects they would have been less impressed and considerably less inclined towards leniency if it had been their lands he'd attacked. Edward, perhaps regretting his earlier outburst, sent Llywelyn, his wife Lleucu, his six sons and five others "under safe custody at the king’s expense" to the Tower. They were granted either three pence a day for their maintenance (Llywelyn and Lleucu, which names English scribes often spelt as Thloellin and Leuken or similar) or two pence (the others). Edward also removed Payn Turberville from office and replaced him with the more moderate John Giffard. By June 1317, only Llywelyn and two of his sons - their names spelt Lewelin Pren, Griffin and Yevan - are mentioned as prisoners in the Tower, the others presumably having been released.  Llywelyn Bren ultimately suffered a terrible fate, removed from the Tower by Hugh Despenser sometime in 1318 and grotesquely executed in Cardiff - murdered in fact, as Despenser had no authority to commit such an act.
The campaign against Llywelyn Bren was of short duration, but expensive; William Montacute alone took 150 men-at-arms and 2000 footmen, at Edward II's expense, and the royal treasury, as usual, was in a parlous state. Trouble also broke out elsewhere in Wales, thanks to the long-running feud between Edward's chamberlain John Charlton and his wife Hawise Gadarn and her uncle Gruffydd de la Pole, over the lordship of Powys. In March 1316, Edward told Chancery "If this riot be not hastily quenched much greater evil may come in other parts of Wales," and sent his steward John Cromwell to "bridle the evildoers and staunch the riots," granting him ten pounds for his expenses.  Fortunately, these riots didn't develop into anything more serious.
I'd like to point out that neither of these rebellions (or riots or uprisings) was aimed at Edward II personally, and in fact he was rather popular in Wales, the land of his birth. In September 1327, a Welsh plot to free him from Berkeley Castle was discovered by William Shalford, Roger Mortimer's deputy justice of Wales; the plotters, who included Rhys ap Gruffydd named above and Gruffydd Llwyd, who rode to Rhuddlan to inform Edward I of Edward II's birth in 1284, either fled to Scotland or were imprisoned at Caernarfon Castle for eighteen months. The (English) chronicler Thomas Walsingham wrote with reference to Edward II at the end of the fourteenth century: "the Welsh in a wonderful manner cherished and esteemed him, and, as far as they were able, stood by him grieving over his adversities both in life and in his death, and composing mournful songs about him in the language of their country, the memory of which lingers to the present time, and which neither the dread of punishment nor the passage of time has destroyed." [6.]
1) Vita Edwardi Secundi, ed. N. Denholm-Young, p. 66. Anything not otherwise cited in this post comes from the Vita, pp. 66-68.
2) Calendar of Patent Rolls 1313-1317, pp. 384, 433; Foedera, II, i, p. 283.
3) Calendar of Chancery Warrants 1244-1326, p. 437.
4) Calendar of Close Rolls 1313-1318, pp. 263, 274-5, 283, 419; Calendar of Fine Rolls 1307-1319, p. 276.
5) Chancery Warrants, 436-437; Frederick Devon, Issues of the Exchequer: being a collection of payments..., p. 131.
6) Historia Anglicana, ed. H. T. Riley, volume 1, p. 83.