When war broke out in August 1914, VII London Bde had only just arrived at Perham Down on Salisbury Plain for its annual training camp, and it was immediately recalled to London to mobilise under the command of Brevet Colonel Chambers.
After completing their mobilisation the 2nd London Division's artillery brigades moved to the country round Hemel Hempstead, Berkhamsted and Kings Langley in Hertfordshire to begin war training.

On the outbreak of war, TF units were invited to volunteer for Overseas Service.
On 15 August 1914, the War Office issued instructions to separate those men who had signed up for Home Service only, and form these into reserve units.
On 31 August, the formation of a reserve or 2nd Line unit was authorised for each 1st Line unit where 60 per cent or more of the men had volunteered for Overseas Service.
The titles of these 2nd Line units would be the same as the original, but distinguished by a '2/' prefix.
In this way duplicate batteries, brigades and divisions were created, mirroring those TF formations being sent overseas.
Eventually these too were prepared for overseas service and 3rd Line reserve units were formed to produce reinforcement drafts to the others.
The duplicate 2/VII London Brigade was formed in September 1914.
When war broke out in August 1914, VII London Bde had only just arrived at Perham Down on Salisbury Plain for its annual training camp, and it was immediately recalled to London to mobilise under the command of Brevet Colonel Chambers. After completing their mobilisation the 2nd London Division's artillery brigades moved to the country round Hemel Hempstead, Berkhamsted and Kings Langley in Hertfordshire to begin war training.
On the outbreak of war, TF units were invited to volunteer for Overseas Service. On 15 August 1914, the War Office issued instructions to separate those men who had signed up for Home Service only, and form these into reserve units. On 31 August, the formation of a reserve or 2nd Line unit was authorised for each 1st Line unit where 60 per cent or more of the men had volunteered for Overseas Service. The titles of these 2nd Line units would be the same as the original, but distinguished by a '2/' prefix. In this way duplicate batteries, brigades and divisions were created, mirroring those TF formations being sent overseas. Eventually these too were prepared for overseas service and 3rd Line reserve units were formed to produce reinforcement drafts to the others. The duplicate 2/VII London Brigade was formed in September 1914.
7th County of London Brigade, Royal Field Artillery