Pope Francis wants to heal a 1,000-year rift between the Catholic and Eastern Orthodox churches

Pope Francis is hosting a landmark meeting with one of his Eastern Orthodox counterparts, Patriarch Kirill of Russia, in Cuba today, the first time a pope and a Russian patriarch have met since the two churches split nearly a millennium ago.

In a joint statement, the two sides announced that the leaders will hold a two-hour meeting at Cuba’s international airport and conclude with a declaration with both men’s signatures.

"The Holy See and the Moscow Patriarchate hope that it will also be a sign of hope for all people of good will," the statement read. "They invite all Christians to pray fervently for God to bless this meeting, that it may bear good fruits."

One of the aims of Francis’s papacy has been to reconcile with members of the Eastern Orthodox Church, and to that end he held a high-profile meeting in 2013 with Patriarch Bartholomew I of Constantinople, considered the spiritual leader of all Orthodox Christians.

But the Russian Orthodox Church, the second-largest single Christian denomination after Catholicism, has resisted overtures from several consecutive popes, and for that reason today’s meeting holds significance.

The religious divide that led to a 1,000-year rift

The Great Schism, as it’s known, occurred in 1054 after Pope Leo IX in Rome and the patriarch of Constantinople ex-communicated each other from the church. The two sides didn’t begin communicating until about 50 years ago, in 1964, when Pope Paul VI and Greek Patriarch Athenagoras met in Jerusalem. The next year, in simultaneous ceremonies, the two men undid the excommunications of 1054 that had set the schism in motion.

Historically, there existed particular enmity between the Catholic Church and the Russian Orthodox Church. Russia’s anti-Western sentiments can be traced back to the Great Schism, when the East perceived the Catholic Church as trying to control it from afar. More recently, the Russian Orthodox Church has accused the Catholic Church of poaching converts in Russia and Ukraine, core Orthodox territory. The Vatican and Russia only established diplomatic ties in 2009.

Even so, this meeting took almost two years of diplomacy to organize, a Vatican official told the Guardian. Bitterness ran deep enough that the patriarch refused to meet in Europe, and other countries in Latin America were too overwhelmingly Catholic. Hence the meeting taking place in Havana, which is thought to be a neutral spot for the two churches.

A spokesperson for the Russian Orthodox Church said in a statement that the two leaders would in part discuss the persecution of Christians in the Middle East and North Africa, a situation that requires "closer cooperation between Christian Churches."

But given his past outreach to Orthodox patriarchs, Pope Francis is likely seeking a larger signal of cooperation.

"Something can only be considered historic after it becomes history," Justo L. Gonzalez, author of several books on early Christian history, told NPR.