The privileges and graces with which God had surrounded the Immaculate Conception of His Blessed Mother Mary were reflected upon her happy parents, Joachim and Ann. We find, therefore, that in the Sixth Century Justinian built a church at Constantinople in honor of St. Ann.
Devotion to the grandparents of the divine Redeemer spread almost everywhere in the East. The Syrians venerated St. Ann under the name of Dina on July 25; other eastern Churches place her feast on another date. Pope Leo III placed pictures of Joachim and Ann in the Church of St. Mary Major. Gregory XIII in 1584 inserted the feast of St. Ann in the Roman Missal.
At Rome in the patriarchal basilica of St. Paul the precious relic of the arm of St. Ann was venerated even in the days of St. Bridget of Sweden, who obtained a very small portion of it as a gift. St. Ann then appeared to her and showed her how to venerate and care for sacred relics. Leo XIII and Benedict XV have given several fragments of this arm of St. Ann to celebrated sanctuaries dedicated to her in Canada and in Normandy, where God has been pleased to honor them by performing various miracles.
Her feast was extended to the Universal Church by Pope Leo XIII in 1879. Pope Benedict XV visited her chapel outside the Vatican; this was the first time after 1870 that a Pope left the Vatican.
(Source: The New Roman Missal, Rev. F. X. Lasance)