In the eleventh century, the successful struggle which had been made by Gregory VII., with the aid of the Countess Matilda, for the principle of papal supremacy exerted a marked influence upon the religious life of the time and gave an undoubted impetus to the idea of conventual life for women, as during this period many new cloisters were established. It will be readily understood that the deeds of the illustrious Tuscan countess had been held up more than once to the gaze of the people of Italy as worthy of their emulation, and many women were unquestionably induced in this way to give their lives to the Church. In the Cistercian order alone there were more than six thousand cloisters for women by the middle of the twelfth century. It was during this same eleventh century, when a woman had helped to strengthen the power of the Church, that the influence of the Madonna--of Mary, the mother of Christ--began to make a profound impression upon the form of worship. A multitude of Latin hymns may be found which were written in honor of the Virgin as far back as the fifth century, and in the mediaeval romances of chivalry, which were so often tinged with religious mysticism, she often appears as the Empress and Queen of Heaven. All through the mediaeval period, in fact, there was a constant endeavor to prove that the Old Testament contained allusions to Mary, and, with this in view, Albertus Magnus put together a _Marienbibel_ in the twelfth century, and Bonaventura edited a _Marienpsalter_. Therein, the gates of Paradise, Noah's ark, Jacob's ladder, the ark of the Covenant, Aaron's rod, Solomon's throne, and many other things, were held up as examples and foreshadowings of the coming of the Blessed Virgin; and in the sermons, commentaries, and homilies of the time the same ideas were continually emphasized. A collection of the Latin appellations which were bestowed upon the Madonna during this time contains the following terms, which reveal the fervor and temper of the age: _Dei genitrix_, _virgo virginum_, _mater Christi_, _mater divinae gratiae_, _mater potens_, _speculum justitiae_, _vas spirituale_, _rosa mystica_, _turris davidica_, _domus aurea_, _janua coeli_, _regina peccatorum_, _regina apostolorum_, _consolatrix afflictorum_, and _regina sanctorum omnium_.