Essex has always been one of the areas of the UK most threatened by invasion and as such has a long history of garrisons of regular troops and raising of militia forces for home defence.
Initially volunteer units were nationally unregulated with authority placed in the hands of the Lord Lieutenant for each county. As there was no national funding for uniform or weapons, for the most part volunteer units were rich men's playthings so that a military title could be added to a local dignitaries name.
In 1757 the Militia Act created recognised volunteer forces in counties including Essex and provided funding for uniform and weapons. This new force was required to train and to be embodied at times of national threat for home defence such as the Napoleonic Wars.
On 12 May 1859 , following the Crimea Campaign, Parliament authorised Lord Lieutenants of Counties, including Essex, to raise volunteer rifle corps, engineer and artillery units.
In 1872 the volunteer corps began to be incorporated into volunteer battalions attached to regiments with the Essex Volunteer Rifles joining the Essex Regiment. This was completed by 1881 although some volunteers hung onto their names a little longer.
In 1907 the volunteer battalions became Essex Territorial Regiments and continued as such until the demise of the Regiment in 1963.
The Essex Yeomanry came into being in 1909 with the amalgamation of volunteer cavalry units and then became a territorial force