Born in Frenchwood House, Lancashire,[2] to a recusant English Roman Catholic family able to trace an uninterrupted pedigree back to Conishead Priory in 1325, Gillow was the son of a magistrate, Joseph Gillow (1801-1872), and his wife, Jane Haydock (1805-1872), a descendant of Christopher Haydock, a Lancashire politician and a member of another prominent recusant English Roman Catholic family, the Haydocks of Cottam.[2][3]
In 1878 Gillow married Eleanor McKenna, daughter of John McKenna, of Dunham Massey Hall,[2] with whom he had seven children.[5] In marrying into the McKennas, Gillow secured himself a private income which allowed him to pursue his antiquarian interests.[6]
Gillow published various researches into the history of Roman Catholicism in Lancashire, but his greatest achievement was A Literary and Biographical History, or Bibliographical Dictionary of the English Catholics: from the Breach with Rome, in 1534, to the Present Time (5 vols, 1885-1902), available in Google Books. To fit his material into the five volumes allotted to him by his publishers, he needed to abbreviate the later volumes.[6]
Cardinal Gasquet described the dictionary as a ‘veritable storehouse of information’, however, until 1986, no index was available.[7]
Gillow was appointed honorary recorder of the Catholic Record Society at its foundation in 1904, and was a frequent contributor.[8]
