Monasteries were an ever-present feature of the Medieval landscape and perhaps more than half were devoted solely to women. The rules and lifestyle within a nunnery were very similar to those in a male monastery. Nuns took vows of chastity, renounced worldly goods and devoted themselves to prayer, religious studies and helping society's most needy. Many nuns produced religious literature and music, the most famous among these authors being the 12th century CE abbess Hildegard of Bingen.
Christian women who vowed to live a simple ascetic life of chastity in order to honor God, acquire knowledge and do charitable work are attested to from the 4th century CE if not earlier, just as far back as Christian men who led such a life in the remote parts of Egypt and Syria. Indeed, some of the most famous ascetics of that period were women, including the reformed prostitute Saint Mary of Egypt (c. 344-c. 421 CE) who famously spent 17 years in the desert.
Over time ascetics began to live together in communities, although they initially continued to live their own individualistic lives and only joined together for services. As such communities became more sophisticated so their members began to live more communally, sharing accommodation, meals and the duties required to sustain the complexes which formed what we would today call monasteries and nunneries.
The monastic idea spread to Europe in the 5th century CE where such figures as the Italian abbot Saint Benedict of Nursia (c. 480-c. 543 CE) formed rules of monastery conduct and established the Benedictine Order which would found monasteries across Europe. According to legend, Benedict had a twin sister, Saint Scholastica, and she founded monasteries for women.
Such nunneries were often built some distance from monks' monasteries as abbots were concerned that their members might be distracted by any proximity to the opposite sex. Monasteries such as Cluny Abbey in French Burgundy, for example, prohibited the establishment of a nunnery within four miles of its grounds. However, such separation was not always the case and there were even mixed-sex monasteries, especially in northern Europe with Whitby Abbey in North Yorkshire, England and Interlaken in Switzerland being famous examples. It is perhaps important to remember that, in any case, the medieval monastic life for men and women was remarkably similar, as the historian A. Diem here notes: