'Absolutely outstanding' 12-century picture stone unearthed in Germany likely depicts bishop who brought Christianity to region

A man doing home construction in Germany has discovered a rare boulder with a 12th-century carving — a "picture stone" that may depict a Christian bishop who visited the area around 800 years ago.

The medieval find is a "sensation," as there are only about 20 other known picture stones in the region, Detlef Jantzen, chief archaeologist of Mecklenburg-Vorpommern, the state where it was found, told Live Science. Known in German as "bildstein," these stones have been found along the Baltic coast in parts of what is now Germany and Poland. While they vary in style and form, they typically show people with a few identifying attributes, such as clothing.

The newfound carving may depict Otto of Bamberg (lived 1060 to 1139), a bishop who served royalty and a missionary who sought to convert people in Pomerania, which is now part of Germany and Poland.

"Whether the bildstein is showing Otto or not: This is an absolutely outstanding find, that leads us back to the time when Christian religion first came to Pomerania, brought by Otto, who is at the same time famous for his success to negotiate peace between the Polish duke and the Pomeranian nobility," Jantzen, who also works with the State Office for Culture and Monument Preservation, told Live Science in an email.

The stone was found in August, when Peter Wittenberg, a homeowner in the village of Klotzow, began moving soil by his house so he could reach its foundation. He found the 3-foot-long (1 meter) boulder just below the ground's surface, but he only realized it was "something special" when he saw that it had a "very old fashioned carving," Jantzen said.

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Wittenberg's architect connected with an art historian, and soon, news of the "outstanding find" spread to the state archaeological office, which brought it to a laboratory to examine, Jantzen said.