In 1883 Riegl wrote his dissertation on the Romanesque Church of St. Jacob, Regensburg. His dissertation on the North Portal of the so-called "Scottish" church of St. Jacob, argued that the interface patterns on the portal stemmed not from Irish manuscripts, but from Carolingian miniatures.
St. Jacob is the largest church in the city, the Church is impressive not only because of the its towers, but also its interior with two altars fashioned by the famous wood carver Tilman Riemenschneider. Another gem is the high altar by Friedrich Herlin.