On the 28th November 1756, a little French girl was born at Barfleur, France, and baptized Julie Frances Catherine. She was educated at the Benedictine convent at Valognes, and when eighteen she ran the little village school at Barfleur.

She was a pioneer in education, basing her teaching on the De La Salle method. In 1807, at Cherbourg, she and three other young women took religious vows before Abbe Cabart, who had encouraged her in her work - the beginning of the Sisters of the Christian Schools of Mercy. She was named superior and took the name Marie Madeleine. It was not until 1832 when she obtained the abbey of St. Sauveur le Vicomte that the congregation finally began to expand and flourish. She died on July 16 at St. Sauveur, venerated for her holiness and miracles, and was canonized in 1925. Her feast day is July 17.

St Joseph's Convent School was founded in 1910 by the Sisters of St Marie Madeleine Postel, whose aim was to provide a good education in a warm and loving atmosphere. This simple aim is as appropriate today for Catholic pupils and those of other denominations as it was when St Joseph's was founded over 100 years ago.  St Joseph's Convent School became St Joseph's College in September 2010, with a change to co-educational status throughout the whole School.