<P> A militia / mɪˈlɪʃə / is generally an army or some other fighting organization of non-professional soldiers , citizens of a nation , or subjects of a state , who can be called upon for military service during a time of need , as opposed to a professional force of regular , full - time military personnel , or historically , members of a warrior nobility class ( e.g. , knights or samurai ) . Generally unable to hold ground against regular forces , it is common for militias to be used for aiding regular troops by skirmishing , holding fortifications , or irregular warfare , instead of being used in offensive campaigns by themselves . Militia are often limited by local civilian laws to serve only in their home region , and to be serve only for a limited time ; this further reduces their use in long military campaigns . </P>
ordinary citizens called out to fight in an emergency were part of what was known as the
militia