Its original purpose was home defence , although the establishment of the Territorial and Army Volunteer Reserve in 1967 involved a restructuring and revised doctrine leading to the provision of routine support for the regular army overseas . Reservists in the past also served as constables or bailiffs , even holding positions of civic duty as overseer of their parish . The more modern Yeomen of the 18th century were cavalry-based units , which were often used to suppress riots ( see the Peterloo Massacre ) . Several units that are now part of the Army Reserve bear the title " militia " , reflecting their origins as part of that organisation prior to the formation of the Special Reserve in 1907
Peterloo Massacre
Peterloo Massacre
Army Reserve (United Kingdom)