**2. A Brief Analysis of Some Liturgical Hymns Alluding to the Gate of Heaven**

In this section we will briefly present a select set of medieval Latin liturgical hymns that praise or appeal to the Virgin Mary, designating her with the metaphors "gate of heaven" (*ianua Coeli*), "door of Paradise" (*porta Pzaradisi*), or some other formula alluding to the power of mediation of Mary before her divine Son to facilitate the eternal salvation of the faithful. To better appreciate the conceptual and symbolic evolution of these medieval hymns, we will expose them sequentially in groups corresponding to the centuries in which each was written.

A preliminary precision is now required. Within the strict limits of an academic article, we have selected, as a representative sample of a much larger totality, those fragments of liturgical hymns that seemed to us the most significant for the topic we proposed. Although valid, ours is not the only possible choice. Obviously, another researcher who wants to carry out an investigation with a similar approach to ours will be able to choose many other examples of similar hymns, which will undoubtedly lead to the same or similar results.
