The Siege of Lowestoft was a brief Parliamentarian operation in March 1643 during the First English Civil War, when Oliver Cromwell suppressed a small Royalist rising that had secured the port of Lowestoft in Suffolk. Cromwell's Eastern Association forces seized arms and took the local gentry prisoner to Cambridge. [1] Unlike much of Suffolk Lowestoft was sympathetic to the royalists partly due to her commercial rivalry with the Parliamentarian Great Yarmouth. [2] It was the only battle in the Civil War within the otherwise solidly Parliamentarian Suffolk. [3] Prisoners taken by Cromwell included the courtiers John Pettus [4] and Thomas Knyvett.