The timing of the Pope’s message to Patriarch Kirill was significant, since the Pontiff met with Orthodox Patriarch Bartholomew I of Constantinople during his visit to the Holy Land. The Moscow patriarchate has shown a keen sensitivity about claims that the Patriarch of Constantinople is the leader of the Orthodox world.

In the past, several attempts to arrange a meeting between the Roman Pontiff and the Patriarch of Moscow have failed, with Russian Orthodox officials invariably saying that such a “summit meeting” would be premature until existing disputes between Rome and Moscow are resolved. Those disputes have escalated in recent months, as Russian Orthodox leaders complain that Byzantine-rite Catholic leaders have incited political tensions in Ukraine. The strength of the Ukrainian Catholic Church has been a longstanding source of irritation for the Moscow patriarchate, which views Ukraine as its own “canonical territory.”