It is said that they controlled Ashridge Priory and Edington Priory in England, but this has been completely repudiated in an article by Richard Emory in the journal Speculum (1943), who attributes the original connection to Helyot's Dictionnaire des Ordres Religieux, which was compiled in Paris between the late 17th and early 18th centuries.
All that is known concerning him is collected by Paul Sabatier in the "Introduction" to the Speculum perfectionis (1898).
The site and the Great Hall are extensive, and the writer Geoffrey Ashe argued in an article in the journal Speculum that it was the base for the Arthur of history.
A copy was edited in the Sacrorum Conciliorum nova et amplissima collectio of Giovanni Domenico Mansi in the 18th century, and more recently a new edition has been published by Benjamin Z. Kedar in Speculum (Vol. 74, 1999).
This organization had been developed in the 13th century by Vincent of Beauvais in his Speculum naturale and had also been used by Bartholomaus Anglicus in his De proprietatibus rerum and by Thomas of Cantimpré in his Liber de natura rerum.
Many medieval authors refer to Herman's work, for instance Albert the Great (Albert von Bollstädt, Albertus Magnus), instructor to Thomas Aquinas, in his work Speculum astronomiae.
He also edited the English works of John Fisher, Bishop of Rochester (1876); Thomas Baker's History of St John's College, Cambridge (1869); Richard of Cirencester's Speculum historiale de gestis regum Angliae 447–1066 (1863–1869); Roger Ascham's Schoolmaster (new ed., 1883); the Latin Heptateuch (1889); and the Journal of Philology.
Paul Magdalino, 'Aspects of twelfth century Byzantine Kaiserkritik', Speculum 58 (1983), 326-46 and reprinted in Paul Magdalino, Tradition and Transformation in Medieval Byzantium (Ashgate publishing, 1991), No.
This phenomenon is the source of the Roman name for the lake, Speculum Dianae (Diana's Mirror).
While subdean he was involved in a dispute with the precentor of the cathedral, John Featley, with regard to some capitular appointments, and was attacked by him in a tract entitled Speculum Mapletoftianum.
The manuscript is perhaps most known because it was bound with a manuscript of Vincent of Beauvais' popular encyclopedia Speculum historiale and a spurious map on vellum, the notorious "Vinland map"- no such map is included with a second, older Hystoria/Speculum manuscript volume found more recently.