(Feb) 4. Our Lady of the Pillar, at Saragossa, in Spain. So named, because, according to the tradition, the Blessed Virgin appeared to St. James the Major on a pillar of jasper,
A.D. 36, and commanded him to build her a church, which the Spaniards hold to have been the first dedicated to Our Lady. (Beutereus, 1. i., c. 2 et 3.)
Image (click it to enlarge): "Portrait of Our Lady of the Pilar" by Juan Correa, c. 1695 A.D.
The following account of the miraculous appearance of the Blessed Virgin to the Apostle St. James the
Greater, in Spain, was issued by the Sacred Congregation of Rites on August 7, 1723, and later inserted in the lessons of the office of the feast of Our Lady
of the Pillar:
all the places that Spain offers for the veneration of the devout, the most illustrious is doubtless the sanctuary consecrated to God under the invocation of the Blessed Virgin, under the title of our Lady of the Pillar, at Saragossa. According
to ancient and pious tradition, St. James the Greater, led by Providence into Spain, spent some time at Saragossa. He there received a signal favour from the Blessed Virgin. As he was praying with his disciples one night, upon the banks of the Ebro, as the
same tradition informs us, the Mother of God, who still lived, appeared to him, and commanded him to erect an oratory in that place. The apostle delayed not to obey this injunction, and with the assistance of his disciples soon constructed
a small chapel. In the course of time a larger church was built and dedicated, which, with the dedication of Saint Saviour's, is kept as a festival in the city and Diocese of Saragossa on the 4th of October."
Link: Overview of 17th c. Historical Calendar of the Feasts of the B.V.M.
Calendar of the Feasts of the Blessed Virgin, With the Foundations and Churches Dedicated to Her", from Abbé Orsini's work, "Life of the Blessed Virgin Mary, Mother of God", Imprimatur 1858 A.D.