Early Irish communities of religious women have never been adequately studied. However, Irish hagiography, unique among medieval saints' lives because of the incidental details it offers, provides much evidence about nuns and nunneries. Because the Irish saints' lives were written by monks, this information also reveals the monastic attitude towards nuns. Hagiography shows that many nunneries were established before the seventh century. But these communities began to disappear soon after, so that today only the location of a dozen or so are known to historians. Women's religious communities disappeared for a combination of reasons, political, social, economic, and spiritual. Secular society was hostile towards these communities from the start because they consumed a resource considered precious by men: unmarried women. Male ecclesiastics held an ambiguous attitude towards nuns and nunneries. They believed that women could attain salvation as well as themselves. Yet the entire church hierarchy of Ireland was dominated by supposedly celibate men, whose sacral functions and ritual celibacy were threatened by women, especially women's sexuality. Hagiography expressed this threat with the theme of sinful, lustful nuns; even the spirituality of women vowed to chastity and poverty was suspect. This attitude affected the structure, organization, and eventually the survival of women's monastic enclosures in early Ireland.