This is a pretty big deal, folks:

The Ecumenical Patriarch of Constantinople Bartholomew I will attend Pope Francis’s inaugural Mass. The Ecumenical Patriarchate Press Office informed AsiaNews about the decision, noting that this is the first time such an event occurs since the Catholic-Orthodox split in 1054, an important sign for Christian unity.

The ecumenical patriarch will be accompanied by Ioannis Zizioulas, metropolitan of Pergamon and co-president of the Joint International Commission for Theological Dialogue between the Roman Catholic and the Orthodox Church, as well as Tarassios, Orthodox Metropolitan of Argentina, and Gennadios, Orthodox Metropolitan of Italy.

Relations between Catholics and Orthodox have been improving since the Second Vatican Council through mutual visits, acts of friendship and theological dialogue.

Under Benedict XVI, the dialogue picked up in earnest after a lull. In trying to promote it, the pope suggested ways to express the primacy of Peter’s successor that could be acceptable to the Orthodox, finding his inspiration from the undivided Church of the first millennium.

Catholic ecumenism has met however with great resistance from the Russian Orthodox Church and the Moscow Patriarchate, seat of the ‘Third Rome’.

The head of the Russian Orthodox Church’s Department for External Relations, Metropolitan Hilarion of Volokolamsk, said on Thursday that a meeting between the pope and Patriarch Kirill of Moscow was “possible but the place and timing will depend on how quickly we will overcome the consequences of the conflicts from the turn of 1980s and 1990s”.

The issue of the Ukrainian Catholic Church is at the core of the “conflicts” to which Hilarion was referring. Although it was unbanned following the collapse of the Soviet Union, it was left without its original churches, which had been seized by the Communists under Soviet rule and later transferred to the Orthodox Church.

Still, “on several occasions, Pope Francis has shown spiritual sympathy towards the Orthodox Church and a desire for closer contacts,” Hilarion said.