Complex sentence: Over the centuries the panels from the altarpiece have been moved, damaged by fire, some sold, some taken during wars, and in 1934, when all the panels were again in St. Bavos, the lower left panel, The Just Judges, was stolen.
Split into simpler sentences: Over the centuries the panels from the altarpiece have been moved and damaged by fire, while some have been sold, and some taken during wars. After all the panels were again returned to St. Bavos, in 1934 the lower left panel, The Just Judges, was stolen.