11 As, with a heart full of confidence and hope, We place this first Encyclical of Our Pontificate under the Seal of Christ the King, We feel entirely assured of the unanimous and enthusiastic approval of the whole flock of Christ. The difficulties, anxieties and trials of the present hour arouse, intensify and refine, to a degree rarely attained, the sense of solidarity in the Catholic family. They make all believers in God and in Christ share the consciousness of a common threat from a common danger.
Source: Summi Pontificatus (Vatican.va)