« CREATOR ALME SIDERUM ». – Hymn of Vespers for the season of Advent, attributed, with little foundation, to s. Ambrogio; its author was nevertheless inspired by him. It is a threefold invocation of faith, love, and hope addressed to God, creator of the universe, redeemer of humanity fallen into sin, and judge at the end of the world. This vision of the Last Judgment is attuned to the Gospel of the first Sunday of Advent.
BIBL.: G. G. Belli, Gli inni del Breviario tradotti, Rome 1857, p. 110; L. Venturi, Gli inni della Chiesa, 3rd ed., Florence 1880, p. 144; S. G. Pimont, Les hommes du Brevuaire romain, II, Paris 1880, pp. 13–28; C. Albini, La poésie du Brevuaire, Lyon n.d., p. 106; G. Bossi, Gli inni del Breviario romano, versione chimica, Rome 1919, p. 32; A. Mirra, Gli inni del Breviario romano, Naples 1947, p. 84.