(In the First and Second Parliaments of Oliver Cromwell's Protectorate, there was a general redistribution of seats and Derbyshire elected four members; the traditional arrangements were restored from 1659.)
This influence was originally established by the formidable Bess of Hardwick, whose second husband was a Cavendish and who in 1572 manoeuvred to secure her son from that marriage a seat as MP for the county - a considerable honour for a young man from what was then a family of only minor importance.
Its population grew swiftly (having reached 237,170 by 1831); but the electorate has been estimated at only 3,000 or 4,000 in the second half of the 18th century, and was probably not much higher by the time of the Reform Act.
Few of the industrial workers, of course, had the vote since they were not property owners, and in the early 19th century political unrest was common - most notably the "Pentrich Revolution" or "Derbyshire Rising" of 1817.
At the 1831 election their sitting Tory MP was summarily swept out of his seat for supporting a destructive amendment to the Reform Bill.