Patriarch Alexiy II, the head of the Russian Orthodox Church, presided over a huge revival of faith throughout Russia and a restoration of the authority of the Church after decades of Soviet repression. He became leader in 1990 as the Soviet Union was collapsing, and at his death his church believers were estimated to include about two thirds of Russia’s 142 million population.

Alexiy’s 18-year-reign, however, was marred by allegations that he and many other leading church officials had collaborated with the KGB. His successful rise to power took place in the 1970s and 1980s during the leadership of Leonid Brezhnev when the Orthodox Church was controlled by the KGB and dissident priests were thrown into jail. It was during this period that he rose rapidly through church ranks, becoming the number two in the influential external affairs section of the patriarchate.

Nonetheless he demonstrated courage and independence in August 1991 when, during the attempted KGB coup, he denounced the arrest of the Soviet leader Mikhail Gorbachev, excommunicated the plotters and broadcast over loudspeakers to Soviet troops surrounding the White House, the headquarters of the Government.

The Patriarch’s success in restoring the power and influence of the world’s biggest Orthodox Church was accomplished by forging an alliance with the leaders of the new Russian state, presidents Boris Yeltsin and Vladimir Putin. Under Soviet rule, religion was suppressed and thousands of churches were destroyed or converted into museums, warehouses and stables. The domes of the churches were stripped of their gold.

Under Alexiy’s leadership, they were reopened and regilded as the Church’s popularity surged. The huge Cathedral of Christ the Saviour in central Moscow, destroyed by Stalin and replaced by a swimming pool was restored to its former splendour.

While anxious to establish the Church’s independence for the first time since the 1917 Bolshevik Revolution, Alexiy nevertheless kept in step with the Kremlin’s foreign policy. He was a strong critic of Nato and US intervention in Yugoslavia, of the US-led war in Iraq and a staunch defender of the rights of ethnic Russians in countries of the former Soviet Union.

He often complained that Russia’s new religious freedom put his Church under severe pressure and bitterly criticised other Christian churches’ attempts to poach adherents from the Orthodox Church. He was especially wary of the Roman Catholic Church, which he accused of “proselytism”, and refused repeatedly to meet Pope John Paul II and his successor Benedict XVI. Unity with the Orthodox Church was a long-cherished dream of John Paul II, who frequently referred to his desire for the Church in Europe to breathe with “two lungs” — the rational spirit of Latin Christianity and the intuitive mysticism of Byzantine Orthodoxy. He wrote three addresses aimed at healing the 1,000-year fracture between Roman Catholicism and Orthodoxy. But despite such gestures as John Paul II returning to Moscow from the papal study the Russian icon of the Virgin of Kazan, Alexiy remained cold (he claimed the icon was not original but a copy) and took umbrage when the Catholic Church began to create new dioceses for its believers without permission from the Orthodox Church.

In 1997 Alexiy successfully lobbied for the passage of a religious law that placed restrictions on the activities of religions in Russia other than Orthodoxy, Islam, Judaism and Buddhism. Under his leadership the Church also vehemently opposed schismatic Orthodox churches in neighbouring Ukraine, claiming the Ukrainian Orthodox Church should remain under Moscow’s control.

The main reason for his disagreement with the Greek Catholics was a property dispute between the Catholic and Orthodox churches in Ukraine, where the Greek Catholic Church, which was banned and dispossessed by Stalin, took back hundreds of parishes from the Orthodox Church in the 1990s.

However, Alexiy lived long enough to see another significant religious dispute resolved. In 2007 he signed a pact with Metropolitan Laurus, the leader of the breakaway Russian Orthodox Church Outside Russia, to bring the churches closer together. The ROCOR had split off in 1927 after the Moscow church’s leader declared loyalty to the Communist Government.

Alexiy remained prudent after the fall of communism in Russia, ruling out investigation against church officials accused of links to the Soviet secret services. The British-based Keston Institute, which monitors religious freedoms in former communist countries, presented research suggesting that Alexiy’s career may have been aided by assistance he gave the KGB while a young priest in Tallinn.

The British-based KGB defector Oleg Gordievsky alleged that Alexiy worked for the KGB for more than 40 years, and was mentioned in KGB archives under the code name Drozdov. The Moscow patriarchy denied this claim, although Alexiy himself did acknowledge that under communism bishops were forced to compromise with Soviet power. Within the church Alexiy was never an innovative leader and he was opposed to liberal policies. However, he rejected and denounced anti-Semitic currents in religious thinking which have always been a powerful influence in the Russian Orthodox Church. He repeatedly affirmed the traditional stand of the Orthodox Church against homosexuality and opposed the gay parades in Moscow and St Petersburg. He called homosexuality “an illness and a distortion of the human personality like kleptomania”.

The Patriarch was an impressive character with a benign expression and a powerful air of moral authority. He vigorously advocated the return of the Orthodox Church to the centre of Russian life and spirituality, but was accused of making the Church a powerful force for Russian nationalism.

He was born Alexei Mikhailovich Ridiger in 1929 in Tallinn, the capital of what was then sovereign Estonia. His father was a Russian of Swedish descent, originally from a German Baltic aristocratic family. He entered the Leningrad Theological Seminary during the Stalin regime in 1947 and graduated two years later. He went on to the Leningrad Theological Academy and graduated in 1953. In 1950 he was married to the daughter of a priest but was divorced a year later for reasons that have remained private.

He was ordained a deacon in 1950 by the Metropolitan Gregory of Leningrad, and appointed rector in the Tallinn diocese. In 1957 he was appointed rector of the Cathedral of the Dormition in Tallinn and a year later he was elevated to the rank of archpriest. In 1961 he as a tonsured monk in the Trinity Cathedral of the Trinity Lavra St Sergius.

In 1961 he was chosen to be the Bishop of Tallinn and Estonia and elevated to the rank of archbishop three years later. On February 25, 1968, he became Metropolitan at the age of 39.

From 1986 until his election as Patriarch he was Metropolitan of Novgorod and Leningrad. After the death of Patriarch Pimen he was chosen to be the new Patriarch of the Russian Orthodox Church on the basis of his administrative experience and was considered “intelligent, energetic, hardworking, perceptive and businesslike”. He also had a reputation as a conciliator and at the time Archbishop Chrysostom remarked that “with his peaceful and tolerant disposition Patriarch Alexiy will be able to unite us all”. Under his leadership the New Martyrs and Confessors of Russia, who suffered under communism, were glorified, beginning with the Grand Duchess Elizabeth. In 2000 the All-Russian Council glorified Tsar Nicholas II and his family as well as many other New Martyrs.

Patriarch Alexiy II, Patriarch of Moscow and All Russia, was born on February 23, 1929. He died on December 5, 2008, aged 79