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Learning About

Harlech Castle


The Princes of Snowdonia

By the Middle Ages, the main kingdoms of Wales were Gwynedd, Powys and Deheubarth. On the whole, Gwynedd was the most powerful kingdom in Wales, mainly due to the fact that Snowdonia’s mountainous terrain was an aid to defend the area. Gwynedd’s supremacy can be traced back to Maelgwn Gwynedd’s reign during the C6. In his day, Maelgwn was Wales’ most powerful leader.

In 825, a new dynasty was established in Gwynedd, by Merfyn Frych. His successor was Rhodri Mawr, one of Gruffudd ap Cynan’s ancestors. Gruffudd ap Cynan re-established Rhodri Mawr’s dynasty in 1098. Llywelyn ab Iorwerth and Llywelyn ap Gruffudd, two of Gwynedd’s most celebrated leaders, were both members of this dynasty.

The Welsh Principality was formally established in 1267, as part of the Treaty of Monmouth, when Edward I acknowledged Llywelyn ap Gruffudd as Prince of Wales. Llywelyn ap Gruffudd was killed in Cilmeri in 1282 and his only heir, Princess Gwenllïan, was sent to live in a convent in Sempringham, Lincolnshire. Dafydd ap Gruffudd, Llywelyn ap Gruffudd’s brother, inherited the title of Prince of Wales, but the dynasty soon came to an end, when Dafydd was executed in 1283. This marked the completion of the Edwardian Conquest of Wales.

The Welsh Principality established by the Princes of Gwynedd did survive, however, as the area wasn’t included as part of the English kingdom. When Edward I’s son, Edward of Caernarfon, became Prince of Wales in 1301, he received the Welsh Principality, as it had been designated in 1267. Until the Act of Union between England and Wales in 1536, Wales was split in two parts: the Principality and the Marches. ‘The Principality’ is now considered to be the whole of Wales, as it is geographically designated today.


1039: Iago ab Idwal, King of Gwynedd died. Gruffudd ap Llywelyn ap Seisyll became King of Gwynedd, claiming to be a relation of Rhodri Fawr, through his mother, Prawst.

c.1055: Gruffudd ap Cynan was born in the village of Swords, near Dublin. He was the son of Cynan ab Iago ab Idwal and grandson of Iago ab Idwal former king of Gwynedd.

1063: Gruffudd ap Llywelyn ap Seisyll was killed. According to one tradition, Cynan ab Iago (Gruffudd ap Cynan’s father) killed him.

1075: Gruffudd ap Cynan returned to Gwynedd from Ireland, with the intention of re-establishing the kingdom of his grandfather, Iago ab Idwal.

1099: Gruffudd ap Cynan succeeded to gain Anglesey. This gave him grounds to expand his lands in Gwynedd.

1137: Gruffudd ap Cynan died and his son, Owain Gwynedd (Owain ap Gruffudd) became King of Gwynedd.

1163: Owain Gwynedd paid homage to King Henry II in Woodstock.

1165: In July / August, Owain Gwynedd sent his first letter to Louis VII of France, to try to persuade him to lead a military campaign against Henry II. The title ‘Prince of Wales’ was coined for Owain Gwynedd.

1167: Owain Gwynedd and Lord Rhys of Deheubarth attacked Owain Cyfeiliog, leader of Powys, but Henry II remained the main threat to the Principality of Gwynedd.

1170: Owain Gwynedd died. His lands were shared between his sons, Iorwerth Drwyndwn (‘the flat nose’), Maelgwn, Dafydd and Rhodri.

1171: The original, Latin version of ‘Historia Gruffud vab Kenan’ was written.

1173: Llywelyn ab Iorwerth (Llywelyn Fawr, ‘the Great’) was born. It is said that he was born in Dolwyddelan.

1174: Iorwerth Drwyndwn died.

1188: Llywelyn ab Iorwerth began his attack against his uncles, Maelgwn, Dafydd and Rhodri.

1201: An agreement was formed between Llywelyn ab Iorwerth and King John of England, confirming Llywelyn’s lands in Gwynedd.

1204/5: Llywelyn ab Iorwerth married Joan, King John’s illegitimate daughter. Five children were born to them: Dafydd, Gwladus, Marared, Susanna and Elen. Llywelyn was already father to two illegitimate children: Gruffudd and Gwenllïan.

1216: Llywelyn ab Iorwerth held a Welsh Parliament in Aberdyfi.

1220: The English Crown recognised Dafydd ap Llywelyn, rather than Gruffudd ap Llywelyn, as Llywelyn ab Iorwerth’s successor.

1221: The work of building Castell y Bere in Llanfihangel y Pennant began.

c.1225: Llywelyn ap Gruffudd was born to Gruffudd ap Llywelyn and his wife, Senena. Llywelyn ap Gruffudd was Llywelyn ab Iorwerth’s grandson.

c.1230: Llywelyn ab Iorwerth commissioned the building of Dolbadarn Castle in Llanberis.

1237: Princess Joan, wife of Llywelyn ab Iorwerth, died.

1237-40: Following the death of Princess Joan, Llywelyn ab Iorwerth built a priory in remembrance of her in Llanfaes, Anglesey.

1240: Llywelyn ab Iorwerth died. He was buried in Aberconwy Abbey. His successor was Dafydd ap Llywelyn.

1241: Dafydd ap Llywelyn surrendered the hundredth of Tegeingl to Henry III.

1244: Gruffudd ap Llywelyn died as he tried to escape from the Tower of London.

1246: Dafydd ap Llywelyn died. His lands were shared between his nephews, Owain and Llywelyn ap Gruffudd.

1255: Llywelyn ap Gruffudd defeated his brothers and established himself in Gwynedd Uwch Conwy.

1262: Llywelyn ap Gruffudd coined a new title for himself: ‘Prince of Wales and Lord of Snowdonia’.

1267: The treaty of Monmouth between Llywelyn ap Gruffudd and Edward I was signed.

1278: Llywelyn ap Gruffudd and Eleanor de Montford were married at Worcester.

1282: In June, Princess Gwenllïan was born to Llywelyn ap Gruffudd and his wife, Eleanor de Montfort. Eleanor died while giving birth to Gwenllïan. On December 11th, 1282, Llywelyn ap Gruffudd was killed in Cilmeri and Princess Gwenllïan was sent to a convent in Sempringham, Lincolnshire. She was raised there and died there, not knowing anything of her royal connections in Wales. Llywelyn ap Gruffudd was succeeded by his brother, Dafydd.

1283: Dafydd was caught by Edward I’s army and subsequently tried and hanged for treason. Edward I claimed that this was a trial against ‘the last of a family of traitors’. He was disembowelled and quartered and parts of his body were sent to four different cities. This marked the end of the Edwardian conquest of Wales.

1369: Owain Lawgoch claimed Gwynedd. Owain was a nephew of Llywelyn and Dafydd ap Gruffudd (son of their brother, Rhodri).

1378: Owain Lawgoch was killed by the Scot, John Lamb. Lamb was employed as a soldier by the English Crown.

1400: Owain Glyndŵr launched his rebellion by attacking the town of Ruthin. Owain Glyndŵr announced himself as Prince of Wales in Glyndyfrdwy.

1404: Glyndŵr held a Parliament in Machynlleth.

1406: Owain Glyndŵr sent the Pennal Letter to Charles VI, King of France. The letter demonstrates Glyndŵr’s vision for establishing a free Wales, to establish an independent Welsh church and two Welsh universities.

1415: Owain Glyndŵr refused King Henry V of England’s offer of a pardon.