Complex sentence: This used to be the capital of the area and up until the late industrial revolution, the town was the 5th biggest in Derbyshire, after Derby, Chesterfield, Matlock and Buxton.
Split into simpler sentences: This used to be the capital of the area. Up until the late industrial revolution, the town was the 5th biggest in Derbyshire, after Derby, Chesterfield, Matlock and Buxton.