The central panel of the triptych had over the centuries become blackened with the sprinkling of perfume that the monks use as they worship.
The hugely important and stunning painted wood panel is now visible in its original coloured glory, showing a pale-faced Jesus with black curly hair and rosy cheeks.
His hand has three digits raised and two down as if blessing the person looking at him.
He has a halo and is wearing a gown and is perched on his mother’s knee and she too has a halo.
The monks at the Monastery of St Stephen on an island in Lake Hayq in the north of the African country believe the icon, known as The One Who Listens, to be miraculous.
The artist had great skill, which is particularly obvious in the detail of Mary’s robes.
In the central panel are three other figures, two archangels, Michael and Gabriel, armed with swords ready to protect the saviour and the third, St Stephen, after whom the monastery is named.
The side panels have 12 figures upon them all looking inwards towards the central picture.
They include Abuna TeklelyesusMoa, who sponsored the work, various saints including St Peter and St Paul, and abbots from the monastery.
It is one of the most celebrated icons in Ethiopia and is now housed in a special museum with other ancient relics.
The British charity The Ethiopian Heritage Fund sent experts to preserve the painting that had previously been covered with varnish.
Blair Priday from the charity, said: “This icon is one of the most celebrated in Ethiopia and because of its veneration, over time, the central panel had become blackened and was later painted over with thick layers of varnish as protection.
“The faces of the mother and child were barely visible.
“The varnish was carefully removed so it regained the original luminosity.
“The icon’s repair was undertaken by Laurie Morocco, a foremost icon restore, who camped in the monastery’s grounds while he did the work.
“In the mid 15th century a new technique of painting on wood with an undercoating of Gesso was introduced resulting in a much more luminous effect.
“When the varnish was removed by Laurie, one of the glories of Ethiopian art was visible once more.
“St Stephen’s was a very important monastery and seat of learning, and although it was raided and lost some of its relics, many remained including a beautiful cross, manuscripts and this icon.
“This ancient seat of learning now has a museum where these incredible treasures are displayed in a small museum within the monastery
“We could not have carried out the work without the support of the Bureau of Culture and the Holy Synod of the Ethiopian Church and our expert advisor Jacques Mercier.”
Christianity was adopted by the Ethiopians in the fourth century when King Ezra, ruler of the Axumite kingdom, was converted.
The country boasts one of the world’s oldest illustrated Christian manuscripts – the Garima Gospels – which the charity has also conserved.
The charity has also been working on the rock churches of Tigray in the highlands of north east Ethiopia.
These are built high in the sandstone cliffs that dominate the landscape.
The churches are carved out of the rock and contain many beautiful paintings of Christian saints many of which are indigenous to Ethiopia.
In a church in Bahera, the saints on the church pillars had been splashed with lime wash which has now been cleaned off.
The frescos that cover the walls of Debta Tsion are currently being conserved.