Every July 25, the two-week-long celebration in the small Spanish city of Santiago de Compostela reaches its highpoint with High Mass in the Cathedral of Santiago, the Cathedral of St. James. A capacity crowd of 1,200 worshippers fills the cathedral — among them the king of Spain, or his representative from the Royal Family. Amid half a month of feasting, and dancing, and music, and fireworks, the Mass on the feast day of the apostle and martyr is the heart of Catholic Spain’s national festival.