A number of British volunteers, including Tom Wintringham, David Marshall and Ramona and Nat Cohen, and Scots nurse Annie Murray, arrived in Spain during August–September 1936.

The Thälmann Battalion later formed part of XII International Brigade and fought in the Siege of Madrid, including the Battle of Ciudad Universitaria.

[1][2] Another group of British volunteers – among them Jock Cunningham and John Cornford – fought with the French-speaking Commune de Paris Battalion, in the XI International Brigade.

In January 1937, the survivors of No.1 Company joined with 450 new British, Irish, and Dominion volunteers at Madrigueras, near Albacete, International Brigades headquarters.

En route to the railway station at Albacete he was accidentally shot in the arm by the battalion commissar, necessitating transfer of command to Tom Wintringham.

In a single day's bloody fighting on 12 February against Moors of the 7th Tabor of Melilla, part of the 8th Regiment of Francisco Franco's Army of Africa, the British Battalion suffered 275 casualties in No.1, No.3, and No.4 companies – leaving 125 riflemen fit for duty.

On the third day of the battle the battalion was temporarily routed, but under the leadership of Cunningham and brigade commissar Frank Ryan, staged a counter-attack, singing the Internationale, in what would become known as the “Great Rally”.

The following day the British were ordered to advance on Mosquito Ridge, a piece of high ground which overlooked the battalion's original objectives.

As they left Villanueva de la Cañada they were bombed by Junkers aircraft from the Condor Legion and shelled by Nationalist artillery.

The two-hour barrage and devastating heat caused heavy casualties and prevented the battalion reaching Mosquito Ridge before Franco's army rushed reinforcements to defend the position.

On 25 August the battalion attacked a strong Francoist position at Purburrel Hill, and was repelled by intense rifle and machine gun fire.

The following day another assault was made on the hill, supported by the XVth Brigade antitank artillery battery, and this time the attack succeeded.

They arrived at Victoria Station on 7 December, to be met by a crowd of supporters including Clement Attlee, Stafford Cripps, Willie Gallacher, and Will Lawther.