Berswordt Altar

The Master of the Berswordt Altar (sometimes called the Master of the Crucifixion in the Marienkirche at Dortmund) was a German painter, active in the area around Dortmund during the 14th and 15th centuries. A number of works around Westphalia, including one in Bielefeld, are attributed to him.

Reference:
http://en.wikipedia.org/wiki/Master_of_the_Berswordt_Altar