Up to a million people are expected to gather in Madrid's Colon Plaza Sunday for an open-air mass in which Pope John Paul will canonize five new Roman Catholic saints

The mass will be the major event of the pontiff's two-day visit to Spain, which began Saturday. The five new saints were 20th century priests and nuns in Spain, including Father Pedro Poveda Castroverde, who was executed by republican forces during the Spanish Civil War. On Saturday evening, the pope addressed 600,000 exuberant youths at an airbase outside Madrid, urging them to become "artisans of peace" and counter a spiral of violence and terrorism he said was sweeping the world. The pope was greeted upon arrival in the Spanish capital by King Juan Carlos, Queen Sofia, Prime Minister Jose Maria Aznar and a cheering crowd of thousands. In his opening remarks, John Paul called for world peace and urged Spain to draw on its Roman Catholic heritage to build a united Europe amid a diversity of cultures. In turn, the Spanish monarch thanked the pope for his repeated condemnations of terrorism suffered by the people of Spain.