"Karoli Magni Regis Constitutio de Scholis per singula Episcopia et Monasteria instituendis," addressed to the Abbot of Fulda. Baluzius, Capitularia Regum Francorum, T. i., p. 202. Inaugural Address delivered to the University of St. Suggestions for Academical Organisation, with Especial Reference to Oxford. By the Rector of Lincoln. Goethe, Zahme Xenien, Vierte Abtheilung.
The system of double monasteries, or monasteries for both men and women, is as old as that of Christian monasticism itself, though the phrase "monasteria duplicia" dates from about the C6. The term was also sometimes applied to twin monasteries for men; Bede uses it in this sense with reference to Wearmouth and Yarrow, while he generally speaks of a double monastery as "monasterium virginum."