12 When the Church, in the days immediately succeeding her institution, wasoppressed beneath the yoke of the Caesars, a young Emperor saw in the heavens across, which became at once the happy omen and cause of the glorious victorythat soon followed. And now, to-day, behold another blessed and heavenly tokenis offered to our sight-the most Sacred Heart of Jesus, with a cross rising fromit and shining forth with dazzling splendor amidst flames of love. In thatSacred Heart all our hopes should be placed, and from it the salvation of men isto be confidently besought.
Source: Annum Sacrum (Vatican.va)