Definition of English Civil War in English:

proper noun

• The war between Charles I and his Parliamentary opponents, 1642–9.

Civil war broke out after Charles refused to accede to a series of demands made by Parliament. The king's forces (the Royalists or Cavaliers) were decisively defeated by the Parliamentary forces (or Roundheads) at the Battle of Naseby (1645), and an attempt by Charles to regain power in alliance with the Scots was defeated in 1648. Charles himself was tried and executed by Parliament in 1649