More than 80 years ago, workers in a cathedral in the Bavarian city of Augsburg uncovered a previously unknown pair of murals depicting the life and death of St. John the Baptist. But exactly how old the murals were remained a mystery—until now. full story here
Hmmm...? Interesting find... but I have to question the authors claim of the work as being "one of the oldest Christian artworks in Europe". There are far older works. These paintings from catacombs in Rome date from the 2nd century AD before Christianity was legalized by Constantine:
There are still more works dating after the Edict of Milan 313 AD in which Constantine legalized Christianity.
Some of the greatest Christian works from the Byzantine era as well as the Celtic/Hiberno-Saxon/Migratory Period predate the year 1000 AD.
For example, the brilliant mosaics in the mausoleum of Galla Placidia in Ravenna date from the 5th century AD...
... while the Book of Kells dates from the 9th century.
Large Irish crosses such as this date from the 8th-12th C. AD although there are smaller and more crude crosses that predate these.