What Will Happen When the Pope Meets the Patriarch?

The latest diplomatic coup for Pope Francis I—whose papacy has been marked by an ever-more expansive foreign policy—is the announcement of an interesting development in relations between the Roman Catholic and the Russian Orthodox churches, relations that have been more-or-less non-existent for more than 1000 years.

Pope Francis delivers his homily during the Epiphany Mass at St. Peter's Basilica in Vatican City, Vatican, on Jan. 6, 2016. Franco Origlia/Getty Images

Russian Patriarch Kirill celebrates a Christmas service in Christ the Savior Cathedral in Moscow on Jan. 7, 2015. Orthodox Christians celebrate Christmas on Jan. 7 in the Middle East, Russia, and other Orthodox churches that use the old Julian calendar instead of the 17th-century Gregorian calendar adopted by Catholics, Protestants, Greek Orthodox, and commonly used in secular life around the world. Kirill Kudryavtsev/AFP/Getty Images