Ecumenical Patriarch Bartholomew of Constantinople has handed over a "tomos" of autocephaly to Metropolitan Epifaniy of the new Orthodox Church in Ukraine.
Bartholomew presented the document at a church service in Istanbul on January 6, after signing it during a ceremony the previous day.
The historic document grants the Orthodox Church in Ukraine independence, or autocephaly, and ends more than 330 years of Russian religious control in Ukraine.
The patriarch urged the new church in Ukraine to "strive for unity and peace" with believers who remain under the jurisdiction of the Moscow Patriarchate and to "help them understand that Ukraine deserves a united church body."
"Unity has been restored," Metropolitan Epifaniy said during the ceremony in Istanbul's St. George's Cathedral. "Now we are united."
At the January 5 signing ceremony, Bartholomew said that Ukrainians could now enjoy "the sacred gift of emancipation, independence, and self-governance, becoming free from every external reliance and intervention."
Ukrainian President Petro Poroshenko, who attended the two-day events, said on January 6: "The 'tomos' is one more act declaring the independence of Ukraine."
Following the mass, both Poroshenko and Epifaniy attended a traditional Orthodox event on the Bosphorus in which dozens of men braved the cold and jumped into the waters to grab a cross flung by Patriarch Bartholomew.
Metropolitan Epifaniy was expected to take the document back to Kyiv later, where it will be displayed on January 7 in the Sophia Cathedral complex.
Bartholomew announced the decision to recognize Ukraine's request for an autocephalous church in October.
In December, Ukrainian Orthodox leaders agreed on the creation of a new national Orthodox church and elected the 39-year-old Epifaniy to head that church.
Russia long opposed such efforts by the Ukrainians for an independent church, which intensified after Russia seized Ukraine's Crimean Peninsula in March 2014 and began supporting separatists shortly thereafter in parts of Ukraine's eastern regions of Donetsk and Luhansk.
The announcement by Bartholomew, who is considered the leader of the 300-million-strong worldwide Orthodox community, came amid deepening tension over efforts by Ukrainian Orthodox churches to formally break away from Russia's orbit.
It also prompted the Russian Orthodox Church to announce days later that it was ending its relationship with the Ecumenical Patriarchate in protest.
Vladimir Legoida, a Russian Orthodox Church spokesman, denounced the tomos on January 5 as "a document that is the result of irrepressible political and personal ambitions."
It had been "signed in violation of the canons and therefore not possessing any canonical force," Legoida said in a statement.