St Gertrude was of an illustrious family, born at Eisleben, or Islebe, in Upper Saxony, and sister to St. Mechtildes. At five years of age she was offered to God in the Benedictine nunnery of Rodalsdorf, and at thirty was chosen abbess of that house in 1251; and the year following was obliged to take upon her the government of the monastery of Heldelfs, to which she removed with her nuns. In her youth she studied Latin, as it was then customary for nuns to do; she wrote and composed in that language very well, and was versed in sacred literature. Divine contemplation and devout prayer she always looked upon as the principal duty and employment of her state, and consecrated to those exercises the greatest part of her time. The passion of our Redeemer was the favourite object of her devotions; and in meditating on it, or on the blessed Eucharist, frequently she was not able to contain the torrents of tears which flowed from her eyes. She spoke of Christ and of the mysteries of his adorable life with so much unction, and in such transports of holy love, as to ravish those who heard her. Ecstacies and raptures of the divine love, and the gifts of divine union in prayer, were familiar to her. She mentions that once hearing those words, "I have seen the Lord face to face," sung in the church, she saw, as it were, a divine face, most beautiful and charming, whose eyes pierced her heart and filled both her soul and body with inexpressible delight which no tongue could express. The divine love, which burnt in her breast and consumed her soul, seemed the only spring of all her affections and actions. For this precious grace her pure soul was prepared by the crucifixion of her heats to the world and to inordinate self-love in all its shapes. Watching, fasting, abstinence, perfect obedience, and the constant denial of her own will were the means by which she tamed her flesh and extirpated or subdued whatever could oppose the reign of the most holy will of God in her affections. But profound humility and perfect meekness had the chief part in this work, and laid the foundation of the great virtues end graces to which the divine mercy raised her. Though she was possessed of the greatest natural talents and of most extraordinary gifts of divine grace, her mind was penetrated and entirely filled only with the deepest sentiments of her own nothingness, baseness, and imperfections. It was her sincere desire that all others should have the same contempt of her which she had of herself, and she used to say that it seemed to her one of the greatest of all the miracles of God's infinite goodness that his divine majesty was pleased to suffer the earth to bear her. Though she was the superior and mother of the rest, she behaved I towards them as if she had been the lowest servant and one that was unworthy ever to approach them: and such were the sincere sentiments of her heart. How much soever she gave herself up to the exercises of heavenly [contemplation, she, neglected not the duties of Martha, and was very solicitous in attending to all the necessities of everyone, and in providing all things for them, especially all spiritual helps. Her tender devotion to the mother of God sprang from the ardour of her love for the divine Son. The suffering souls in purgatory had a very great share in her compassion and charity.
We have a living portraiture of her pure and holy soul in her short book of "Divine Insinuations, or Communications and Sentiments of Love," perhaps the most useful production, next to the writings of St. Teresa, with which any female saint ever enriched the church, for nourishing piety in a contemplative state. The saint proposes exercises for the renovation of the baptismal vows, by which the soul entirely renounces the world and herself, consecrates herself to the pure love of God, and devotes herself to pursue in all things his holy will. The like exercises she prescribes for the conversion of a soul to God, and for the renovation of her holy spiritual espousals, and the consecration of herself to her Redeemer by a bond of indissoluble love, praying that she may totally die to herself, and be buried in him, so that he alone, who is her holy love, be acquainted with this her hidden state or sepulchre, and that she may have no other employment but that of love, or what his love directs. These sentiments she repeats with admirable variety throughout the work and, in the latter part, dwells chiefly on the most ardent desires of being speedily united to her love in everlasting glory, entreating her divine Redeemer, by all his sufferings and infinite mercies, to cleanse her perfectly from all earthly affections and spots, that she may be admitted to his divine presence. Her desires were at length fulfilled and, having been abbess forty years, she was called to the embraces of her heavenly spouse in 1292, her sister Mechtildes being dead some time before. The last sickness of St. Gertrude seemed rather a languishing of divine love than a natural fever; so abundantly did her soul enjoy in it the sweetest comforts and presence of the Holy Ghost. Miracles attested how precious her death was in the sight of God. She is honoured with an office in the Roman Breviary on this day. The Lypsanographia, or catalogue of relics kept in the electoral palace of Brunswick-Lunenbourg, printed at Hanover in 1713, in folio, mentions, amongst others, the relics of St. Gertrude in a rich shrine.
The exercises by which St. Gertrude made such sublime advances in the school of divine love all tended to the closest union of her heart to God by the most inflamed desires and purest affections: and were directed at the same time to remove all obstacles to this union by cleansing her soul and purifying her affections by tears of compunction, by the renunciation of sensual delights and the most perfect denial of herself. Hence she prayed continually that by the grace of the omnipotent divine love she might be strengthened to resign herself to holy love, so that nothing of self should remain in her, but should be totally consumed by the flame of holy love, like dust carried away by the wind, so as not to leave the least grain or trace behind. For this exterior action, both of self-denial and of charity, zeal, and all other virtues are necessary; but interior exercises are far more essential, in which the soul must frequently in the day raise herself up to God by the most ardent desires of love, praise, and thanksgiving, and study to die to herself by sincere and repeated sentiments of humility, compunction, meekness, patience, and self-denial.