Dwynwen

Saint Dwynwen (; ), sometimes known as Dwyn or Donwen, in another, she cannot marry him because her father has already promised her to another.

Tradition also credits Dwynwen with studying the healing properties of local herbs, curing ailments of those who sought her help from across Wales.

Ynys Llanddwyn

Following her retreat from court life, Dwynwen withdrew to the small tidal island of Ynys Llanddwyn—off the southwest coast of Anglesey, Welsh poets Dafydd ap Gwilym and Dafydd Trefor recorded the saint's popularity by referencing the pilgrimages to Ynys Llanddwyn.

After the Reformation, activity at the shrine was suppressed. The area fell into disrepair, exacerbated by drifting sand. Pilgrims looking for a holy site increasingly turned to Saint Elian's Well nearby, though some continued to honour Dwynwen at her ruined church. In the late 19th century, the Oxford Movement—which revived some traditional devotional practices within Anglicanism—brought renewed attention to the site. Around 1879 ("the sixtieth year of Queen Victoria"), a plain cross approximately 14 feet high was erected on the island to commemorate Dwynwen.

In 1903, the Hon. F. G. Wynn of Glynllivon, son of the 3rd Baron Newborough, erected a more elaborate Celtic cross on Ynys Llanddwyn, again honouring the saint. Today, the site is part of a nature reserve and remains a popular spot for visitors.

Patronage Besides being recognised as the patron saint of Welsh lovers, Dwynwen is also considered a patron of sick animals.

Dydd Santes Dwynwen (; Welsh for St Dwynwen's Day) is considered the Welsh equivalent of Valentine's Day and is celebrated on 25 January, in honour of Dwynwen, the Welsh patron saint of lovers.

Calendars from the fifteenth century and later assign her feast day to 25 January. However, the 17th-century hagiographer Nicolas Roscarrok placed "St Dwin" on 13 July, suggesting that Dwin and Dwynwen were variants of the same saint. In his records, 25 January commemorates "Dwinwent" or "Damwent". the official Catholic calendar for Wales, nor in the 1995 revision of the Church in Wales calendar.

Present day During the 1960s, a Bangor University student, Vera Williams, sought to revive St Dwynwen's Day by designing Welsh "Valentine's" cards. Local press and businesses embraced the idea, and by 2004, the celebration of 25 January as a feast for Welsh lovers was well established—Gwynedd Council even promoted it. Though overshadowed by Valentine's Day, its recognition continues to spread. A major boost came in 2003 when the Welsh Language Board partnered with the supermarket Tesco to distribute 50,000 free St Dwynwen's Day cards across Wales. One of these cards contained a specially marked heart, entitling the finder to a prize.

Legacy Dwynwen's name endures in several place names, including Ynys Llanddwyn and Porthddwyn on Anglesey in Wales, and the church of "Sen Adhwynn" in Advent, Cornwall.

Welsh composer Joseph Parry wrote the music for "Dwynwen", a chorus penned by Benjamin Williams for the 1896 Llandudno National Eisteddfod.