The Second Council of Nicaea (787 AD)

That from henceforth, no double monastery shall be erected; and concerning the double monasteries already in existence.

We decree that from henceforth, no double monastery shall be erected; because this has become an offence and cause of complaint to many. In the case of those persons who with the members of their family propose to leave the world and follow the monastic life, let the men go into a monastery for men, and the women into a monastery for women; for this is well-pleasing to God. The double monasteries which are already in existence, shall observe the rule of our holy Father Basil, and shall be ordered by his precepts, monks and nuns shall not dwell together in the same monastery, for in thus living together adultery finds its occasion. No monk shall have access to a nunnery; nor shall a nun be permitted to enter a monastery for the sake of conversing with anyone therein. No monk shall sleep in a monastery for women, nor eat alone with a nun. When food is brought by men to the canonesses, let the abbess accompanied by some one of the aged nuns, receive it outside the gates of the women’s monastery. When a monk desires to see one of his kinswomen, who may be in the nunnery, let him converse with her in the presence of the abbess, and that in a very few words, and then let him speedily take his departure.

Ancient Epitome of Canon XX.

Monasteries shall not be double, neither shall monks and nuns live in the same building, nor shall they talk together apart. Moreover if a man takes anything to a canoness, let him wait without and hand it to her, and let him see his relative in the presence of her superior.

It is evident, as Zonaras remarks, that the double monasteries here referred to are not those in which men and women live together, in one house, which in this canon is not tolerated at all, but those which were situated so close together that it was evident there could easily be an entrance from one to the other, these are allowed under certain cautions by this canon.

But not only the Greeks but the Latins also often disapproved of such monasteries. See decree in Gratian, Pars. II., Causa XVIII., Q. II., canon xxviij., and Pope Paschal’s letter (Epis. X) to Didacus, Abp. of Compostella.

Despite all this St. Bridget of Sweden again instituted double monasteries in the XVth century, concerning which Thomas Walsingham, a monk of St. Alban’s Abbey, in England, writes that in 1414, King Henry founded three monasteries, of which the third was a Brigittine, professing the rule of St. Augustine, with the additions called by them the Rule of the Saviour. “These two convents had one church in common, the nuns lived in the upper part under the roof, the brothers on the ground-floor, and each convent had a separate inclosure; and after profession no one went forth, except by special licence of the Lord Pope.”

With regard to the chaplains of nuns, provision is found in Justinian’s Code. (Lib. xliv., De Epis. et clericis.)

This canon is found in the Corpus Juris Canonici, Gratian’s Decretum, Pars. II., Causa XVIII., Q. II., canon xxj.