12th Mechanised Brigade (United Kingdom)

12th Mechanized Brigade
Insignia of 12th Mechanized Brigade
Active	1899 – present day
Country	United Kingdom
Branch	British Army
Type	Mechanized infantry
Part of	3rd (United Kingdom) Division
Garrison/HQ	Bulford Camp
Engagements	World War I Le Cateau Battle of Marne Battle of Aisne First Battle of Ypres (1914) Battle of Messines (1914) Hill 60 Second Battle of Ypres (1915) Battle of Albert Battle of Le Transloy Battle of the Somme First Battle of the Scarpe Third Battle of the Scarpe Battle of Polygon Wood Battle of Broodseinde Battle of Poelcapelle Battle of Passchendaele Battle of Arras (1918) Battle of Hazebroucke Battle of Bethune Advance in Flanders Battle of the Scarpe (1918) Battle of Drocourt-Quéant Battle of the Canal du Nord Battle of the Selle Battle of Valenciennes World War II
Commanders
Notable commanders	Sir Henry Fuller Maitland Wilson Sir Adrian de Wiart Sir John Hawkesworth Daniel Beak Sir Richard Hull Sir Gordon MacMillan

The 12th Armoured Infantry Brigade, formerly the 12th Mechanized Brigade, is a regular brigade of the British Army which has been in almost continuous existence since 1899 and now forms part of 3rd Mechanised Division.

The brigade was first formed in December 1899 as 12th Infantry Brigade and saw action at the Battle of Rensburg, Battle of Norval's Point, Battle of Biddulph's Berg and Battle of Slabbert's Nek.

During the First World War, the 12th Brigade, a regular army formation, was assigned to the 4th Infantry Division. It was dispatched to France, crossing the English Channel on 22 August 1914, as part of the British Expeditionary Force (BEF) and saw action in the First Battle of the Marne beginning in September 1914. It then spent much of the rest of the conflict engaged in trench warfare.

The 12th Brigade was constituted as follows during the war:

From early November 1915 until February 1916 the 12th Brigade was swapped with the 107th (Ulster) Brigade of the 36th (Ulster) Division.

During the Second World War, except for a few brief periods of detachment, the brigade formed part of the 4th Infantry Division, as in the First World War. It was part of the British Expeditionary Force (BEF) and took part in Battle of France and the subsequent Dunkirk evacuation in May–June 1940.

The brigade remained in the United Kingdom for the next two years, preparing and training to repel Operation Sea Lion, the German invasion of England, although that never arrived. It moved to North Africa in February 1943 to take part in the later stages of the Tunisian Campaign and saw action at the Battle of Oved Zara, the Battle of Medjez Plain and the Battle of Tunis. It then took part in the Italian Campaign, moving to Naples in February 1944 and saw further action at the Fourth Battle of Monte Cassino. By October 1944 the 4th Division was taking part in the British Eighth Army's battle on the Gothic Line but was withdrawn in November to spend the rest of the war in Greece, part of the Allied force tasked to prevent civil unrest as rival factions attempted to fill the political vacuum when the Germans withdrew from the country.