The cause of Casimir's cult was taken up by the new Bishop of Vilnius Benedykt Woyna (appointed in 1600). He sent canon Gregorius Swiecicki to Rome with a letter from King Sigismund III Vasa requesting to add the feast of Casimir to the Roman Breviary and Roman Missal. The Sacred Congregation of Rites refused the request but on 7 November 1602 Pope Clement VIII issued a papal brief "Quae ad sanctorum" which authorized his feast "sub duplici ritu" on 4 March but only in Poland and Lithuania. The brief also mentioned that Casimir was added to the ranks of saints by Pope Leo X. In the absence of any earlier known papal document explicitly mentioning Casimir as saint, the brief is often cited as Casimir's canonization. Swiecicki returned to Vilnius with the papal brief and red velvet labarum with the image of Saint Casimir. The city organized a large three-day festival on 10–12 May 1604 to properly accept the papal flag. On the third day, the cornerstone was laid for the new Church of St. Casimir. The coffin of Casimir was taken out of the crypt and elevated to the altar. Swiecicki testified that when the coffin was opened in August 1604 a wonderful smell filed the cathedral for three days.