Moscow, Russia - Metropolitan Kirill, elected on Tuesday as the new leader of 165 million Russian Orthodox believers, is seen as a modernizer who may thaw long icy ties with the Catholic Church.
The first Patriarch elected since the collapse of the Soviet Union in 1991, Kirill, 62, replaces Alexiy II, a conservative credited with reviving the Church and transforming its place in Russian society before his death from illness last month.
Kirill's tenure as the 16th Russian Orthodox Patriarch is likely to be defined by his relations to two powerful institutions: the Kremlin and the Catholic Church.
Some hope Kirill will establish better ties with Catholics than Alexiy, who accused Rome of trying to poach Orthodox believers and resisted meeting the Pope.
Hopes of a thaw have been fueled by Kirill's meeting with Pope Benedict in the Vatican in 2007 and his optimistic comments about better relations with Rome. But Kirill has also echoed Alexei's criticisms of Catholics on occasions.
"Kirill is probably more sympathetic to improving relations with the Vatican," said Professor John Anderson, an expert on Russian Orthodoxy at the University of St. Andrews in Scotland.
"He also has to watch what he says" considering how conservative the rest of the Church is, he added.
On Monday, as delegates gathered for the election, Kirill said in a newspaper interview that there was some way to go before a meeting between the heads of the two churches would be possible.
"A meeting between the Patriarch and the Pope will become possible only when there are conclusive signs of real and positive progress on issues which for a long time have been problematic for our relations," Kirill said.
Like Rome, the Kremlin will loom large over Kirill's tenure.
Alexiy's legacy of pushing the Church back to the center of Russian life after the fall of atheist Communism was in large part based on close ties with political leaders, who helped fund a huge wave of church building.
Church officials are given pride of place at state occasions, while political leaders like Prime Minister Vladimir Putin and President Dmitry Medvedev are filmed visiting churches on major Orthodox holidays.
While this relationship has proved controversial in the past, Kirill is unlikely to change this any time soon, said Canon Michael Bordeaux, head of the Keston Institute that monitors religion in former communist states.
"As it is, the Moscow Patriarchate never criticizes the Kremlin over its internal or external policies ... But I don't think Kirill will start doing that."
"In the Orthodox tradition, which goes back 500 years, the state and the Church work together," he said.
Born in Leningrad, now called St Petersburg, into a priest's family, Kirill was ordained a priest in 1969. He later served as rector of the Leningrad seminary, regarded as one of the one most open to the West.
Before his election as patriarch, Kirill headed the Church's department for external relations, the same role filled by Alexiy II before his election, and one which gave him significant exposure on Russian television.
Kirill was named acting head of the Church on Alexiy's death and made a powerful speech at his mentor's funeral.
He was confirmed in office by a council of 700 priests, monks and laymen, who elected Kirill with 508 out of 677 valid votes after a conclave at Moscow's Christ the Saviour Cathedral.