Middlesex and Westminster Royal Volunteers

A militia force was raised from the civilian population of a county, in order to supplement the regular army in cases of emergency. In Middlesex they were called out at times of unrest. They came to be supplemented by volunteer forces, such as those raised by the 1794 Bill for "encouraging and disciplining such corps and companies of men as shall voluntarily enrol for the defence of their counties, towns and coasts or for the general defence of the Kingdom during the Present War [with France]".

There were around 300 militiamen in Middlesex in 1802. During the Napoleonic Wars this number rose to over 2000 by 1808 and 12,000 by 1812. More volunteer corps were raised in 1859, again in response to threat of French invasion. In 1881 the Army was organised into territorial regiments formed of regular, militia and volunteer battalions. Middlesex militia and volunteer battalions came under the Middlesex Regiment (Duke of Cambridge's Own).