Orthodox Christians in Russia, Greece, Ethiopia and other countries around the world are celebrating Christmas Day today (Thursday, 7 January). The date is taken from the old Julian calendar, which was introduced by Julius Caesar in 46BC as a reform of the Roman calendar. It was replaced by the Gregorian calendar in the majority of Western Europe around 500 years ago.

A special midnight mass was held in the Cathedral of Christ the Saviour in Moscow. Head of the Russian Orthodox Church Patriarch Kirill recited a Christmas Eve liturgy at the mass which was attended by hundreds of worshippers and the Prime Minister Dmitry Medvedev. After the 1917 revolution, Christmas was banned in Russia. People started celebrating it again only after the break up of the Soviet Union.

Christmas services were also held in former Soviet states Belarus and Georgia and in Eastern European countries such as Bosnia, Serbia and Macedonia.

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Russian Patriarch Kirill leads a Christmas service in Moscow's Christ the Saviour cathedralNatalia Kolesnikova/AFP
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Russian Prime Minister Dmitry Medvedev attends a Christmas service in Christ the Saviour cathedral in MoscowNatalia Kolesnikova/AFP
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Belarussian soldiers take part in an Orthodox Christmas service at a military base in MinskSergei Gapon/AFP
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A serviceman of the Belarussian Interior Ministry's special force kisses a cross during a service to celebrate Orthodox Christmas at a military base in MinskVasily Fedosenko/Reuters
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Georgian men march on a street in Tbilisi during Alilo, a religious procession to celebrate Orthodox ChristmasDavid Mdzinarishvili/Reuters
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Children take part in a procession to celebrate Orthodox Christmas in Tbilisi, GeorgiaDavid Mdzinarishvili/Reuters
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Ukrainian children sing Christmas carols as they gather to celebrate Orthodox Christmas at the National Architecture museum in KievValentyn Ogirenko/Reuters
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A woman dressed in traditional costume dances during celebrations of Orthodox Christmas at a compound of the National Architecture museum in Kiev, UkraineValentyn Ogirenko/Reuters
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People gather to receive a piece of traditional bread, marking Orthodox Christmas Day in Belgrade, SerbiaMarko Djurica/Reuters
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Marko Djurica/Reuters
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Marko Djurica/Reuters
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Serbian President Tomislav Nikolic attends the liturgy on Orthodox Christmas in Saborna church in BelgradeMarko Djurica/Reuters
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People watch the ceremonial burning of dried oak branches, a Yule log symbol, in front of Saint Sava church in Belgrade on Orthodox Christmas EveAndrej Isakovic/AFP
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Believers light candles during an Orthodox Christmas service in Saborna church in Belgrade, SerbiaMarko Djurica/Reuters
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Children hold candles during a religious mass to celebrate Orthodox Christmas at the Cathedral of St Clement in Skopje, MacedoniaRobert Atanasovski/AFP

The Greek Orthodox Patriarch of Jerusalem, Theophilos III, led mass at the Church of the Nativity in Bethlehem, considered by many as the birthplace of Jesus. The Church of the Nativity is shared by various Eastern denominations including the ancient Assyrian Church, the Greek Orthodox, Armenian and the Coptic Church, all of which are celebrating Christmas.

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The Greek Orthodox Patriarch of Jerusalem Theophilos III attends a Christmas service at the church of Nativity in the West Bank city of BethlehemAmmar Awad/Reuters

An Eritrean Orthodox Christian service for refugees and migrants was held at a makeshift church in the camp known as The Jungle in Calais. Thousands of migrants continue to live in makeshift camps in the port towns of Calais and Dunkirk in northern France, where they try and board vehicles heading for ferries or through the tunnel in an attempt to reach Britain.

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Well-wishers and volunteers queue to attend an Eritrean Orthodox Christian service for refugees and migrants at a makeshift church in the camp known as The Jungle in Calais, FranceCarl Court/Getty Images
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Eritrean Orthodox Christians pray beneath a depiction of an angel on the wall of a church at The Jungle camp in CalaisCarl Court/Getty Images
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An Eritrean Orthodox Christian arrives to attend a Christmas service at a church in the camp known as The Jungle in Calais, FranceCarl Court/Getty Images

A Christmas morning mass was held in Gaza's Greek Orthodox Church. Out of Gaza's population of 1.5 million, approximately 3,500 are Christian. Some of Gaza's Christian population travelled out of the blockaded strip for the holiday season. For this Christmas season, Israel granted special permission to 800 residents of all Christian denominations to leave Gaza and travel to the West Bank and East Jerusalem, Israeli authorities said.

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Orthodox Christians attend a Christmas mass at the Saint Porphyrios Greek Orthodox church in Gaza CityMohammed Abed/AFP
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A Palestinian Christian woman sits at the Saint Porphyrios Greek Orthodox church in Gaza City during Orthodox Christmas celebrationsMohammed Abed/AFP

Coptic Christians in Egypt celebrated Christmas in Cairo's St Mark Cathedral with Pope Tawadros II, head of the Coptic Church, leading mass. Orthodox Coptic Christians make up about 10% of the country's 90 million people.

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Coptic Christians celebrate Christmas in Cairo, EgyptMohamed El-Shahed/AFP
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Egyptian Coptic Christians celebrate Christmas in CairoMohamed El-Shahed/AFP
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Mohamed El-Shahed/AFP