Gwenllian ferch Llywelyn (June 1282 – 7 June 1337) was the only child of Llywelyn ap Gruffudd, the last native Tywysog Cymru (Prince of Wales). She is sometimes confused with Gwenllian ferch Gruffudd, who lived two centuries earlier.
Lineage
Gwenllian (pronounced using the Welsh letter "ll") was born in the Welsh royal home in Abergwyngregyn near Bangor, Gwynedd. Lady Gwenllian's mother, Eleanor de Montfort, Lady of Wales, died during childbirth, or shortly after on 19 June 1282. She was descended from dual Royal bloodlines; not only was she the daughter of the Welsh Prince of Wales, but her maternal great grandfather was King John of England.

At the mercy of King Edward I
A few months after Gwenllian's birth, north Wales was encircled by the English army of King Edward I. On 11 December 1282 her father, Llywelyn ap Gruffudd, was lured into Builth Castle, ostensibly to sign a treaty, but he was captured there and put to death. Gwenllian's uncle, Dafydd ap Gruffudd, assumed her guardianship, but on 21 June 1283 he was captured with his family at Nanhysglain, a secret hiding place in a bog by Bera Mawr in the uplands of North Wales. Dafydd, severely injured, was taken to Rhuddlan, then moved under guard to Shrewsbury, where he was later executed.

Confinement for fifty years
Gwenllian and the daughters of her uncle Dafydd ap Gruffudd were all confined for life in remote priories in Lincolnshire, and never allowed freedom. It has been speculated that the girls were taken to Lincolnshire from Gwynedd by sea.
Gwenllian was placed in the Gilbertine Priory at Sempringham, where she was held behind high walls until her death fifty-four years later. In committing her to a convent, Edward's aim was not only to prevent her from marrying and having sons who might lay claim to the Principality of Wales, but also to hide her away, unknown to the outside world. He chose the Gilbertines in Lincolnshire because of their remote location in the fenlands and because they were an order in which nuns were hidden from view behind high walls. Gwenllian's royal rank was acknowledged at least once by the English Crown. When writing to the Pope, attempting to secure more money for the Sempringham priory from the Church, the English King stated that "...herein is kept the daughter of the Prince of Wales, whom we have to maintain."
Having been taken from her native land so young, Gwenllian never learned any Welsh. Documents indicate that the priory record-keepers were not even sure how to spell her name correctly; she is listed as "Wencilian" and was herself shown to have signed her name "Wentliane".[1]

Old age and death

Memorial to Princess Gwenllian at Sempringham, England.
Edward III of England, Edward I's grandson, endowed Gwenllian with a pension of £20 per year; this was not money for her personally, simply a sum paid on her behalf to the priory in respect of her food and clothing. Her death there was recorded by the priory's chronicler in June 1337, a few days before her 55th birthday.[2]

Fate of her male cousins
Dafydd's two young sons, heirs to the Principality or Kingdom of Wales, were taken to Bristol Castle, where they were held prisoner; Llywelyn ap Dafydd died there in 1287, four years after his capture, and was buried in the Dominican Church; Owain ap Dafydd survived (his brother); the King of England ordered a cage made of timber, bound with iron, in which to hold Owain ap Dafydd more securely at night. Owain was never released from imprisonment.
King Edward I took the title of "Prince of Wales" for the Crown, bestowing it upon his son, Edward, at a Parliament held in Lincoln in 1301 at the age of seventeen. The title is still given to the heir apparent to the British crown to this day.

Gwenllian in later culture
▪ Gwenllian has been immortalised at least twice in poetry. "Gwenllian", by T. James Jones, was inspired by the site of her memorial stone. "In Sempringham" is by Mererid Hopwood. Hopwood is notable for being the first woman ever to win the Chair at the National Eistedfodd, Wales' top honour for poetry.
▪ Gwenllian is also the subject of "Gwenllian's Lament," also called "Gwenllian's Cradlesong," a song composed by Toby Griffen.
▪ On 26 September 2009, Carnedd Uchaf, in the Carneddau mountain range in Snowdonia, was formally renamed Carnedd Gwenllian in memory of this lost princess of Wales following a lengthy campaign by the Princess Gwenllian Society.[3] The Ordnance Survey added the names Carnedd Uchaf / Carnedd Gwenllian on its maps to be published from 2010 onwards.[4] The original name of Garnedd Uchaf, which is within the Bounds of Abergwyngregyn, is Garnedd Lladron.
▪ A plaque has also been placed at the summit of Mt Snowdon itself.