Ecumenical Patriarch Bartholomew, after signing the tomos of autocephaly for the Orthodox Church of Ukraine on Saturday, stated that the Ukrainian people had been "waiting for this blessed day for seven centuries", that's according to his address to Metropolitan Epifaniy, the leader of the newly-formed OCU.
It formalises an October announcement.
Patriarch of the Greek Orthodox Patriarchate of Antioch and all the East John X said in his letter to Constantinople Patriarch Bartholomew that the granting of independence to new Orthodox Church of Ukraine will not bring peace or harmony either to Ukraine or to the rest of the Orthodox world.
The move has provoked a furious response in Russian Federation, where the Church has broken off links, deepening a split in the worldwide Orthodox Church.
The Russian president, Vladimir Putin, wants the Ukrainian church to stay within Moscow's orbit, and has warned of "a heavy dispute, if not bloodshed" over attempts to reassign ownership of church property.
The decision may the be beginning of a lasting schism in the global Orthodoxy and risks triggering conflicts among Ukraine's Orthodox believers, observers say.
The event at St George's cathedral was broadcast live on Ukrainian television.
"The Tomos is one more act declaring the independence of Ukraine", Ukrainian President Petro Poroshenko said Sunday. On Monday - Christmas Day - a celebration and rally will take place in central Kiev.
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"We will have to see which Ukrainian bishops will join the new church and which other Orthodox churches will recognise it", she added.
The drive for Ukrainian Orthodox independence intensified in 2014, when Russian Federation annexed Crimea and Russia-backed separatists seized a big swathe of territory in eastern Ukraine.
Earlier this year, the Ecumenical Patriarchate of Constantinople overruled its decision dating back to 1686 to transfer its jurisdiction over Kievan Orthodox churches (known as the Kievan Metropolis) to Moscow.
The rival Kiev Patriarchate was born after the collapse of the Soviet Union and its popularity has grown since 2014.
The move is forcing Ukrainian clerics to pick sides between the Moscow-backed Ukrainian churches and the new church as fighting persists in eastern Ukraine between government forces and Russia-backed rebels.
The Patriarchate of Moscow has more followers than the Patriarchate of Constantinople and has challenged it for authority in the past.
The move has dealt a huge blow to Moscow's spiritual authority in the Orthodox world, prompting it to cut all ties with the Constantinople Patriarchate in protest.