Fidel Castro's remains were laid to rest Sunday morning in a private ceremony in Santiago de Cuba, the city where he launched his communist revolution, Cuban officials told CNN.

World leaders are arriving in Havana ahead of Tuesday night’s rally to honor Fidel Castro. Spain’s former king and the presidents of Mexico, South Africa, Nicaragua, Ecuador and Venezuela all plan to attend Castro’s funeral.

Pope Francis had a busy day in Cuba. He met with Fidel Castro at his home and held a massive outdoor mass in Revolution Square where the Pope is urging Cubans not to neglect one another as the country opens up to social and economic changes.