An integral part of the Sunday opening program of the XVIIth All-Sokol Slet is an ecumenical mass in the Cathedral of St. Vitus, Wenceslaus and Adalbert. The blessing for the success of the Slet in the shrine of Czech Patrons and Kings, as Jiří Kuthan called the important symbol of the Czech statehood in his book, will begin at 2 p.m.
After restoration of Sokol Slets following the fall of communism, a holy mass was first held in 2012. Six years ago, the mass was celebrated in front of hundreds of the Slet participants by Cardinal Dominik Duka, concelebrated by patriarch Tomáš Butta and accompanied by the Gaudium Praha choir.