Complex sentence: In a referendum in 1530/31, the citizens of Ulm converted to Protestantism during the Reformation and in 1543 construction work was halted at a time when the steeple had reached a height of some.
Split into simpler sentences: In a referendum in 1530/31, the citizens of Ulm converted to Protestantism during the Reformation. In 1543 construction work was halted at a time when the steeple had reached a height of some.