His Holiness Pope Benedict XVI held a papal audience with Their Serene Highnesses Prince Albert II and Princess Charlene of Monaco on January 12, 2013, at the Vatican.
According to the Vatican Radio, via the Vatican Press Office, His Holiness spoke with the sovereign prince and princess about:
“… the significant contribution of the Catholic Church in the social life of the Principality and various international issues, such as the integral development of peoples and the protection of natural resources and the environment. The couple gave Pope Benedict a picture and book about their ancestor, Cardinal Jerome Grimaldi, who lived in the sixteenth and seventeenth centuries. The Holy Father gave the prince and princess a sanguigna, or red pencil drawing, of St. Peter’s Basilica.”
Afterward, Prince Albert II and Princess Charlene met with the Secretary of State, Cardinal Tarcisio Bertone, and the Secretary for Relations with States, Monsignor Dominique Mamberti.
And, if you are wondering why Princess Charlene was wearing white, again, per the Vatican Press Office, “… in accordance with prescribed ceremonial of the Vatican for Catholic sovereigns, the princess was allowed to dress in white…”