Late Monday, Benedict celebrated an outdoor Mass in the colonial city's main square on a blue-and-white platform crowned by graceful arches in the shape of a bishops' miter. Raul Castro was in the front row, and greeted the pontiff at the end of the service.
Just before the Mass began, a man near an area reserved for international press began shouting anti-government slogans such as "Down with the Revolution! Down with the dictatorship!"
The shouting was heard by an Associated Press photographer and others. The man tried to enter the press area shouting "I only screamed that we are not free" and "nobody paid me anything," but he was restrained by security agents and led away. It was not clear who he was or what happened to him. The government had no immediate comment.
Benedict will spend the night in a house beside the shrine of Cuba's patron saint, the Virgin of Charity of Cobre, where he will briefly pray Tuesday morning.
The statue, which is revered by Cubans Catholic and not, was brought to the Mass on the top of a truck to the joy of the faithful present.
"She is a beauty, the most extraordinary thing," Mercy Serra said as the statue made its way through the crowd. "She is the mother of all Cubans."
Cuban state television broadcast the Mass live, even turning over some of the commentary to a Catholic monsignor.
The crowd included Cubans wearing identical white "Bienvenido" T-shirts, as well as a few hundred Cuban exiles from the United States who flew into Santiago on special charter flights.
"It really does exists, the place where I was born in," said Rita Freixas of Miami Beach, with tears welling up in her eyes. Freixas, who left when she was just one year old, said she nearly came back in 1998 for John Paul's visit. "But my father had just died and he had been in the Bay of Pigs, and I just felt that somehow I would have betrayed him if I had come then."
She arrived with her two grown sons and her best friend; She said with a laugh that while she was waiting for the pope, her two sons had gone off in search of cigars.
Benedict will only be in Cuba for a little over 48 hours, and his limited schedule is sure to disappoint many who want a piece of his attention, from the dissident community, to returning Cuban American exiles and even representatives of imprisoned U.S. government subcontractor Alan Gross.
The Vatican has said the pope has no plans to meet with any of them, citing his advanced age and need for rest. More likely but still unconfirmed is a face-to-face with Fidel Castro, who stepped down in 2006 but remains the father of the revolution and is still referred to as "El Comandante."
A new wild card entered into play with the arrival Saturday of Venezuelan President Hugo Chavez, who is getting radiation therapy for his cancer. Lombardi said no request for an audience had been received but he suggested Chavez could attend Mass on Wednesday.
The one confirmed meeting is the pope's Tuesday encounter with Raul Castro in Havana.
Since taking over from Fidel in 2006, Raul Castro has ushered in a series of economic reforms, legalizing a real estate market, opening the door to limited private enterprise and turning over vast tracts of fallow government land to independent, small time farmers. Pressed by Havana Cardinal Jaime Ortega, he has also cleared Cuba's jails of the last of 75 political prisoners jailed in a 2003 crackdown.
Cuba denies it holds any political prisoners now. Officials refer to dissidents as mercenaries in the sway of its U.S. enemies. Human rights groups say some Cubans remain jailed for their political activities.
The island's Communist government never outlawed religion, but it expelled priests and closed religious schools after Fidel Castro's takeover of Cuba in 1959. Tensions eased in the early 1990s when the government removed references to atheism in the constitution and let believers of all faiths join the Communist Party.