For the purposes of parading, the regular army of the British Army is listed according to an order of precedence. This is the order in which the various corps of the army parade, from right to left, with the unit at the extreme right being highest. Under ordinary circumstances, the Household Cavalry parades at the extreme right of the line. However, when on parade with its guns, it is the Royal Horse Artillery (usually in the form of the King's Troop) that goes to the right. Militia and Territorial Army Units take precedence after Regular units otherwise the Honourable Artillery Company and Royal Monmouthshire Royal Engineers would feature prominently being older than any Regular Regiments.
Cavalry and infantry regiments of the British Army are listed in their own orders of precedence, which dates back to when regiments had numbers rather than names. The order comes from the start of the regiment's service under the Crown, up to 1881 and the "Cardwell Reforms", when the use of numbers was abolished in favour of linking with and using county names. The regiments of the Household Division are always listed first, as they are the most senior, followed by the line regiments. In today's army, which has many regiments formed through amalgamations of other regiments, the rank in the order of precedence is that of the more senior of the amalgamated units. It is for this reason that the Princess of Wales's Royal Regiment, one of the youngest in the army, is ranked second in the line infantry order - it is the direct descendent of the 2nd Regiment of Foot.
Note 1: The 1st Life Guards, 2nd Life Guards and the Royal Horse Guards, were originally termed Horse Guards and given precedence over the Cavalry regiments of the Line. The 1st Royal Dragoons was a line regiment. Note 2: In the sequence for Cavalry of the Line, Cavalry, consisting of Dragoon Guards, come first in the order of precedence with their own numbering sequence. Light Cavalry, consisting of Dragoons, Hussars and Lancers, have their own (single) sequence, hence 1st Dragoons, 3rd Hussars, 5th Lancers, 6th Dragoons, 8th Hussars, 9th Lancers, etc. Note 3: Although one of the antecedent regiments of the Queen's Royal Lancers was the 5th Lancers, this regiment was formed in the 1850s, resurrecting the number of an old regiment and thus ranked in precedence after the 17th Lancers. Note 4: The two individual regiments that make up the Royal Tank Regiment are not included in the order of precedence separately; the RTR (which was formed during the First World War) takes final place in the cavalry/RAC order as a whole.
Note 6: Up to 2006, five line infantry regiments had never been amalgamated in their entire history. In 2006 and 2007, these were amalgamated into large regiments under the planned reorganisation of the infantry:
Note 7: The Royal Marines, as the descendent of the old Army marine regiments of the 17th and 18th centuries, were included in the Order of Precedence after the descendent of the 49th Foot (the Royal Gloucestershire, Berkshire and Wiltshire Light Infantry), which was the last regiment formed prior to the formation of the Royal Marines, when not on parade with the Royal Navy. On the completion of the infantry reorganisation in 2007, the RGBWLI became part of The Rifles, and moved last in the Order of Precedence. As of April 2008 the Royal Marines are considered to no longer be a separate arm of the Royal Navy, but rather an integral part of it. Therefore they no longer have a place amongst the (Army) infantry regiments and now take their place as part of the Royal Navy and parade on the right of the line. Even if there is no other Naval contingent present they are the senior formation on ceremonial occasions. If other contingents of the Royal Navy are on parade, the Royal Marines take their place after them, but before all army regiments and corps. ("The Royal Marines are no longer in the Army order of precedence, but now assume precedence within the Royal Navy at all times." Defence Instructions and Notices (DIN) 2007DIN09-027 "The Precedence of Regiments and Corps in the Army and within the Infantry" released August 2007.) Note 8: Although The Rifles is descended from many numbered regiments, it is last in the order of precedence because the unnumbered regiment The Rifle Brigade has served longest as a rifle regiment. The Royal Gurkha Rifles comes before The Rifles because one of its predecessors (the 2nd Gurkhas) entered service before the Rifle Brigade ceased using its old number (95th). As both the Royal Gurkha Rifles and The Rifles are rifle regiments they come last in the order of precedence, with only the SAS after them (the SAS does not fall into any of the other categories). This is why the Parachute Regiment, which is classed as a line infantry regiment, comes above both.