By early 1282, many of the lesser princes who had supported Edward against Llywelyn in 1277 were becoming disillusioned with the exactions of the royal officers.
On Palm Sunday that year, Dafydd ap Gruffydd attacked the English at Hawarden Castle and then laid siege to Rhuddlan.
The revolt quickly spread to other parts of Wales, with Aberystwyth castle captured and burnt and rebellion in Ystrad Tywi in south Wales, also inspired by Dafydd according to the annals, where Carreg Cennen castle was captured.

Llywelyn, according to a letter he sent to the Archbishop of Canterbury John Peckham, was not involved in the planning of the revolt.
He felt obliged, however, to support his brother and a war began for which the Welsh were ill-prepared.
Personal tragedy also struck him at this time when, on or about 19 June 1282, his wife Eleanor de Montfort, died shortly after giving birth to their daughter Gwenllian.

Events followed a similar pattern to 1277, with Edward's forces capturing Gwynedd Is Conwy, Anglesey and taking the harvest.
The force occupying Anglesey were defeated, however, when trying to cross to the mainland in the Battle of Moel-y-don.
The Archbishop of Canterbury tried mediating between Llywelyn and Edward, and Llywelyn was offered a large estate in England if he would surrender Wales to Edward, while Dafydd was to go on crusade and not return without the king's permission.
In an emotional reply, which has been compared to the Declaration of Arbroath, Llywelyn said he would not abandon the people whom his ancestors had protected since "the days of Kamber son of Brutus" and rejected the offer.

Llywelyn now left Dafydd to lead the defence of Gwynedd and took a force south, trying to rally support in mid and south Wales and open up an important second front.
On 11 December at the Battle of Orewin Bridge at Builth Wells, he was killed while separated from his army.
The exact circumstances are unclear and there are two conflicting accounts of his death.
Both accounts agree that Llywelyn was tricked into leaving the bulk of his army and was then attacked and killed.
The first account says that Llywelyn and his chief minister approached the forces of Edmund Mortimer and Hugh Le Strange after crossing a bridge.
They then heard the sound of battle as the main body of his army was met in battle by the forces of Roger Despenser and Gruffydd ap Gwenwynwyn.
Llywelyn turned to rejoin his forces and was pursued by a lone lancer who struck him down.
It was not until some time later that an English knight recognised the body as that of the prince.
This version of events was written in the north of England some fifty years later and has suspicious similarities with details about the Battle of Stirling Bridge in Scotland.
An alternative version of events written in the east of England by monks in contact with Llywelyn's exiled daughter, Gwenllian ferch Llywelyn, and niece, Gwladys ferch Dafydd, states that Llywelyn, at the front of his army, approached the combined forces of Edmund and Roger Mortimer, Hugo Le Strange, and Gruffydd ap Gwenwynwyn on the promise that he would receive their homage.
This was a deception.
His army was immediately engaged in fierce battle during which a significant section of it was routed, causing Llywelyn and his eighteen retainers to become separated.
At around dusk, Llywelyn and a small group of his retainers (which included clergy), were ambushed and chased into a wood at Aberedw.
Llywelyn was surrounded and struck down.
As he lay dying, he asked for a priest and gave away his identity.
He was then killed and his head hewn from his body.
His person was searched and various items recovered, including a list of "conspirators", (which may well have been faked), and his privy seal.

If the king wishes to have the copy [of the list] found in the breeches of Llywelyn, he can have it from Edmund Mortimer, who has custody of it and also of Llywelyn’s privy seal and certain other things found in the same place.

— Archbishop Peckham, in his first letter to Robert Bishop of Bath and Wells, 17 December 1282 (Lambe
By early 1282, many of the lesser princes who had supported Edward against Llywelyn in 1277 were becoming disillusioned with the exactions of the royal officers. On Palm Sunday that year, Dafydd ap Gruffydd attacked the English at Hawarden Castle and then laid siege to Rhuddlan. The revolt quickly spread to other parts of Wales, with Aberystwyth castle captured and burnt and rebellion in Ystrad Tywi in south Wales, also inspired by Dafydd according to the annals, where Carreg Cennen castle was captured.
Llywelyn, according to a letter he sent to the Archbishop of Canterbury John Peckham, was not involved in the planning of the revolt. He felt obliged, however, to support his brother and a war began for which the Welsh were ill-prepared. Personal tragedy also struck him at this time when, on or about 19 June 1282, his wife Eleanor de Montfort, died shortly after giving birth to their daughter Gwenllian.
Events followed a similar pattern to 1277, with Edward's forces capturing Gwynedd Is Conwy, Anglesey and taking the harvest. The force occupying Anglesey were defeated, however, when trying to cross to the mainland in the Battle of Moel-y-don. The Archbishop of Canterbury tried mediating between Llywelyn and Edward, and Llywelyn was offered a large estate in England if he would surrender Wales to Edward, while Dafydd was to go on crusade and not return without the king's permission. In an emotional reply, which has been compared to the Declaration of Arbroath, Llywelyn said he would not abandon the people whom his ancestors had protected since "the days of Kamber son of Brutus" and rejected the offer.
Llywelyn now left Dafydd to lead the defence of Gwynedd and took a force south, trying to rally support in mid and south Wales and open up an important second front. On 11 December at the Battle of Orewin Bridge at Builth Wells, he was killed while separated from his army. The exact circumstances are unclear and there are two conflicting accounts of his death. Both accounts agree that Llywelyn was tricked into leaving the bulk of his army and was then attacked and killed. The first account says that Llywelyn and his chief minister approached the forces of Edmund Mortimer and Hugh Le Strange after crossing a bridge. They then heard the sound of battle as the main body of his army was met in battle by the forces of Roger Despenser and Gruffydd ap Gwenwynwyn. Llywelyn turned to rejoin his forces and was pursued by a lone lancer who struck him down. It was not until some time later that an English knight recognised the body as that of the prince. This version of events was written in the north of England some fifty years later and has suspicious similarities with details about the Battle of Stirling Bridge in Scotland. An alternative version of events written in the east of England by monks in contact with Llywelyn's exiled daughter, Gwenllian ferch Llywelyn, and niece, Gwladys ferch Dafydd, states that Llywelyn, at the front of his army, approached the combined forces of Edmund and Roger Mortimer, Hugo Le Strange, and Gruffydd ap Gwenwynwyn on the promise that he would receive their homage. This was a deception. His army was immediately engaged in fierce battle during which a significant section of it was routed, causing Llywelyn and his eighteen retainers to become separated. At around dusk, Llywelyn and a small group of his retainers (which included clergy), were ambushed and chased into a wood at Aberedw. Llywelyn was surrounded and struck down. As he lay dying, he asked for a priest and gave away his identity. He was then killed and his head hewn from his body. His person was searched and various items recovered, including a list of "conspirators", (which may well have been faked), and his privy seal.
If the king wishes to have the copy [of the list] found in the breeches of Llywelyn, he can have it from Edmund Mortimer, who has custody of it and also of Llywelyn’s privy seal and certain other things found in the same place.
— Archbishop Peckham, in his first letter to Robert Bishop of Bath and Wells, 17 December 1282 (Lambe
Llywelyn ap Gruffudd