Bruce 's sister Christian Cavendish , Countess of Devonshire was a notable Royalist .
Bruce himself took the side of the Parliamentarians , serving on several county committees from 1644 to Pride 's Purge .
Although Bruce 's sister Christian Cavendish , Countess of Devonshire was a notable Royalist , Bruce himself took the side of the Parliamentarians , serving on several county committees from 1644 to Pride 's Purge .