In about 1131 Gilbert, the parish priest and school master of Sempringham, Lincolnshire, built a convent on his lands for a group of fervent young women from among his pupils. Local people flocked to join; and lay sisters and brothers soon became an integral part of the order. Within the next 60 years 12 houses had been founded, some for canons only, in Lincolnshire and beyond.

The Gilbertines' reputation for sanctity was high, but the order experienced problems from the beginning. The Cistercian abbot, Ailred of Rievaulx, tells the story of a nun of Watton, Yorkshire, who was admitted to the Gilbertine order at the age of only four. As she grew to maturity she became 'frivolous and lascivious', rejecting the discipline of the cloister. Attracted to a young lay brother, she met him in secret: 'She went out a virgin of Christ, and she soon return an adulteress.' Discovering this, and feeling she had disgraced them by her conduct, the younger nuns beat her and imprisoned her in fetters. Only the orders of older and wiser sisters prevented them from flaying and branding her. Frustrated, they persuaded some of the lay brothers to seek out her lover and bring him to them. The young man was pinioned to the ground and his mistress forced to cut off his offending parts and place them in her mouth. She was sent back to prison, and later gave birth to a child; but the very next day she was miraculously healed and restored to her state of virginity as a reward for the repentance she had shown. Later, her fetters fell away. Gilbert, informed of these wonders, decided it would be impious to return her to captivity.

A few years later, in the 1160s, the lay brothers at Sempringham revolted against Gilbert, complaining that they were underfed and overworked, and alleging that the proximity of the nuns and canons produced moral lapses. The order was cleared of the charges of immorality by five bishops, all of whom wrote to Pope Alexander III on Gilbert's behalf, and by Henry II, who took a particular interest in the Gilbertines.

Gilbert himself remained in charge until his death in 1189 at the age of more than 100; he died, according to his biographer, without ever having touched a woman. Within little more than a decade he had been canonized.