William Haydock of Whalley Abbey

According to Joseph Gillow's The Haydock Papers: A Glimpse into English Catholic Life Under the Shade of Persecution and in the Dawn of Freedom (1888), William Haydock, a Cistercian monk, was executed two days after the last Abbot of Whalley Abbey in 1536 for his participation in the Pilgrimage of Grace:

William Haydock was hanged two days later in a field adjoining the abbey known by the name of Le Impe-yard, which signifies a nursery for young trees — the tree of faith that grew so strong in the Haydock family. His body for some reason was allowed to continue suspended on the gibbet entire, and ultimately was secured and secretly removed by his nephew and namesake to Cottam Hall, where it remained until its discovery when the hall was pulled down in the early part of this century.

The Haydocks are one of the great Catholic families of Lancashire, and even if this Haydock has not been beatified or canonized, his brother, Blessed George Haydock, born 20 years later in 1556 took up the mantle of martyrdom. Other family members, like Father George Haydock and his brother Thomas, the publisher of his Haydock Bible, continued to serve the Church. William Haydock's father Vivian also became a priest years after his wife Helen died when George was born. The family motto was the end of verse 20 from the sixteenth chapter of St. John's Gospel: Tristitia vestra vertetur in gaudium (Your sorrow shall be turned into joy!).

According to the Oxford Dictionary of National Biography, Joseph Gillow, 1850 to 1921, was a

biographical lexicographer and genealogist, was born on 5 October 1850 at Frenchwood House, Preston, Lancashire, the son of Joseph Gillow (1801–1872), a magistrate, and his wife, Jane Haydock, née Smith (1805–1872), of Lea. The Gillows were a long-established Roman Catholic yeoman family who could trace an unbroken pedigree back to Conishead Priory in 1325. Gillow's father was a benefactor to the Catholic cause, and his mother was descended, by her mother, from the Haydocks of Cottam, another recusant family.

Joseph Gillow was educated at Sedgley Park, near Wolverhampton (1862–3), and St Cuthbert's College, Ushaw (1864–6), where his uncles and brothers had studied for the priesthood, and discovered there an abiding interest in Lancashire and family genealogy, resulting in his publication of The Tyldesley Diary in 1873, edited from a Lancashire diary kept during the years 1712–14, and in 1888 of The Haydock Papers, a survey of Catholic life in Lancashire as seen through generations of a local family, compiled from family papers and other records.

On 11 September 1878 Gillow married Ella (1850–1945), daughter of John McKenna, a brewer, of Dunham Massey, and secured a private income for the rest of his life. This left him free to pursue his literary studies unimpeded, and he conceived the idea of producing a continuation of Dodd's Church History, covering the period from 1688 onwards and making use of later material collected by the Revd John Kirk and George Oliver, the Catholic directories, and various manuscript sources from Catholic archives. This was followed by a formal commission from the Catholic publishers Burns and Oates to produce the Biographical and Bibliographical Dictionary of the English Catholics in five volumes—volume one appearing in 1885.

As work progressed on the new dictionary, however, it became evident that seven volumes were required, but the publishers were inflexible, insisting that it be completed in five as agreed. To this Gillow reluctantly complied, giving them, in 1902, the last volume, heavily excised and abbreviated. In spite of this the dictionary is still one of the landmarks of Catholic history, particularly useful for the bibliographies of eighteenth- and nineteenth-century Catholics, for which Gillow drew extensively from his own library of 4000 volumes. Cardinal Gasquet described the dictionary as a ‘veritable storehouse of information’ (Gasquet, vii), but as no index was available until 1986, much of the anonymous and pseudonymous literature that Gillow had identified remained locked within its pages.