The origins of this type of monasticism date all the way back to the 4th century beginnings of monasticism in the eastern half of the Roman Empire. One of the earliest of these was a community founded by Macrina the Younger at Annesi.* Double monasteries are known to have existed in the Byzantine Empire until its fall to the Turks in 1453.
[source: Wikimedia Commons]
[Barking Abbey Curfew Tower, photographed by MRSC, source: Wikimedia Commons]
The early double monasteries were almost uniformly headed by an abbess rather than an abbot, as were the Byzantine communities and the Order of Fontevrault. Other double houses were generally headed by an abbot. They also differed in how much contact was allowed between monks and nuns. In all cases the two groups lived separately, but some communities allowed them to intermingle in the church, while others forbade all contact except through a small window in a dividing wall. Though communities differed widely, they share a history of prestige and suspicion.
* Her brother Basil the Great would go on to write a rule for double monasteries and has since receive most of the credit for this type of monasticism. This left Macrina’s foundation to be mostly forgotten and double monasticism in the Byzantine Empire to be known as “Basilian monasticism.”
**There seems to be some connection between the two given the activity of Irish missionaries in Frankish territories at the time, but just how strong the influence was is unclear.
***An example of this would be Hilda of Whitby, whose double monastery hosted the Synod of Whitby, one of the more important church councils of the 7th century.
Lawrence, C. H. Medieval Monasticism. London: Longman, 1984.
Stalley, Roger. Early Medieval Architecture. Oxford: Oxford University Press, 1999.
Stramara, Daniel F. “Double Monasticism in the Greek East, Fourth through Eighth Centuries.” Journal of Early Christian Studies 18, no. 1 (2010): 269-312.
Double Monastery - Wikipedia