The patron saint of the well, St Winefride, was a 7th-century Catholic martyr who according to legend was decapitated by a lustful prince and then miraculously restored to life.

From the 18th century onwards, the well increasingly attracted secular tourism, and it was commonly believed that the well-water had natural healing properties by virtue of its mineral content.

The story of St Winefride, the 7th-century martyr for whom the well is named, is told in two 12th-century Lives: one written by Robert Pennant, prior of Shrewsbury Abbey, and a shorter work of unknown authorship, known as the Vita Prima.

[3] During the late Middle Ages the fame of St Winefride began to spread, as the growth of Marian culture in Europe caused a surge of interest in female saints.

[7] One focal point of Winefride's cult was Shrewsbury Abbey, which had taken possession of the saint's remains in 1137,[8] but Holywell also received large numbers of pilgrims, who came to offer their devotions and to take advantage of the reputed healing power of the water.

On the other hand, Henry's visit may have been politically motivated; by moving north he was positioning himself to head off a potential Welsh invasion, and his devotions at the well sent a message to the people of Cheshire (an area hostile to his rule) that the saint endorsed his victory.

[16] The medieval Welsh poet Tudur Aled said of St Winefride's Well that "every earl used to go, every courtier, every king", and mentions a pilgrimage to the site by Edward IV.

Though the poem gives no indication of the date of this pilgrimage, Edward was active in the area in 1461, around the time of his crowning; like Henry before him, he may have wished to secure a political advantage by showing that Winefride supported his cause.

[18] The chapel that stands on the site today is traditionally said to have been built by Margaret Beaufort, mother of Henry VII, shortly after the 1485 Battle of Bosworth,[19] but there is no contemporary evidence to support this claim.

A 16th-century poem by Siôn ap Hywel says that the funding for the chapel was provided by Abbot Thomas Pennant of Basingwerk in 1512, and modern historians consider this a more plausible account.

[21] In 1534, Henry VIII officially rejected the authority of the Pope and established the Church of England, an act that dramatically altered the nation's religious landscape.

[25] The zeal of the locals helped protect the well chapel from the organized iconoclasm of the following decades, and the income generated by the site gave the authorities good reason not to suppress its operation.

[26] However, anti-Catholic laws were more rigorously enforced during the reign of Elizabeth I, after the papal bull Regnans in Excelsis commanded English Catholics to rebel against their monarch.

[29] In 1605, under the reign of James I, the Jesuit Henry Garnet led a pilgrimage from Enfield to St Winefride's Well, stopping along the way at the homes of several people who were later implicated in the Gunpowder Plot.

[31][32] The backlash against the failed plot resulted in even greater legal intolerance of Catholics and sharper punishments for recusancy (refusal to attend Anglican services).

On 3 November 1629, a crowd of 1,400 "knights, ladies, gentlemen and gentlewomen of divers countries", along with an estimated 150 Catholic priests, gathered at the well to celebrate St Winefride's feast day.

[36][37] The Bishop of St Asaph, in his annual reports to the Archbishop of Canterbury, repeatedly complained about the number of people visiting the well, until in 1637 John Bridgeman returned to the fray.

All but two of the inns at Holywell were closed, the statue of Winefride in the shrine was disfigured, the iron posts around the spring for the support of the bathers were removed, and orders were given to report the names and addresses of every pilgrim.

Medicinal spas had become popular during the Elizabethan era, and 17th-century physicians sought to prove that certain springs could provide powerful health benefits on account of the mineral content of the water.

Bishop John Milner published an account of the incident, in which he collated the testimonies of multiple witnesses and described the event as an "evident miracle" which defied scientific explanation.

This public affirmation of the miraculous power of the well, helped along by the growing Romantic fascination with medieval history, reignited Holywell's pilgrimage tradition.

It had already been observed in 1885 that the drainage schemes connected with the lead mining operations in the Greenfield valley were affecting the output of the well, but the concerns of Holywell residents had been overridden.

A disused mine shaft northwest of Holywell was converted into a pumping plant, which was used to raise an underground water supply and divert it along a drainage tunnel known as the Holway Level.

Restoration work was carried out in the crypt which involved strengthening the masonry, replacing missing flooring slabs, and repairing damage caused by humidity, candle-smoke and fires.

St Winefride's Well remains a popular pilgrimage destination, and its long association with healing has earned Holywell the title of "the Lourdes of Wales".

[62][63] The ritual of the triple immersion has its origin in Robert of Shrewsbury's Life of Winefride, in which Beuno prophesies to Winefride as follows:[64][65] Whoever shall at any time, in whatsoever sorrow or suffering, implore your aid for deliverance from sickness or misfortune, shall at the first, or the second, or certainly the third petition, obtain his wish, and rejoice in the attainment of what he asked for.A 1670 drawing of the chapel shows a small structure to one side of the main spring, labelled "The Little Spring for the cure of sore eyes".

[73] In 1731, a group of Anglican visitors measured the time it took for the well basin to fill, and concluded that the spring "raises more than one hundred tons of water in a minute".

[74] This estimate matches that recorded by Samuel Johnson in his diary when he passed through the area in 1774:[75] The spring called Winifred's Well is very clear, and so copious that it yields one hundred tuns of water in a minute.

It is all at once a very great stream which within perhaps thirty yards of its eruption turns a mill and in a course of two miles eighteen more.In 1859, the draining of the well basin for repair work gave another opportunity of measuring the power of the spring.

[77] The actual cause of the stones' colour may have been natural iron deposits in the water,[78] or the presence of a red-coloured algae, Trentepohlia jolithus, which can still be seen growing on the north wall today.