Clue: Parliamentarians were on one side of this chair, swivelling around (7,5,3)
Answer: ENGLISH CIVIL WAR
Explanation: Definition: Parliamentarians were on one side of this
(CHAIR SWIVELLING)* – the two sides in the English Civil War were the Parliamentarians and Royalists, or, as *1066 And All That* puts it, the Cavaliers (Wrong but Wromantic) and the Roundheads (Right but Repulsive)