It was not a mere expression of the deep and intense Marian piety of Pope Francis, evident, for example, at the Marian shrine of Aparecida in Brazil, where the Holy Father was so moved that he appeared to be in an almost ecstatic state. It was an act in deep continuity with his predecessors going back to Pope Leo XIII.

In the Holy Year of 1900, Pope Leo XIII began the Jubilee celebration by dedicating the entire human race to the Sacred Heart of Jesus. In his concluding remarks, Leo recalled the Emperor Constantine’s victory under the sign of the Cross at the Milvian Bridge in 312: “When the Church, in the days immediately succeeding her institution, was oppressed beneath the yoke of the Caesars, a young Emperor saw in the heavens a cross, which became at once the happy omen and cause of the glorious victory that soon followed. And now, today, behold another blessed and heavenly token is offered to our sight — the most Sacred Heart of Jesus, with a cross rising from it and shining forth with dazzling splendour amidst flames of love.”