1st and 2nd Sussex RGA (V) transferred to the Royal Field Artillery (RFA), forming the I Home Counties Brigade and two batteries of the II Home Counties Brigade respectively. Two companies of the 1st Sussex remained with the RGA to form part of the Kent and Sussex RGA. The I (or 1st) Home Counties Brigade had the following organisation: I Home Counties Brigade, RFA HQ at Drill Hall, Church Street, Brighton 1st Sussex Battery at Brighton 2nd Sussex Battery at Brighton 3rd Sussex Battery at Drill Hall, Marmion Road, Hove; C Subection at Shoreham 1st Home Counties Ammunition Column at Worthing The three batteries were each equipped with four 15-pounder guns. The unit was assigned to the Home Counties Division of the TF. Affiliated to the unit were the 1st Cadet Battalion, 1st Home Counties Bde, RFA, (Imperial Service Cadet Corps) at Brighton, the Steyne School Cadet Corps, and the Brighton Brigade, Sussex Cadets. World War I Mobilisation On the outbreak of war, the TF was mobilised for home defence and units were then 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 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. Duplicate battalions, brigades and divisions were thereby created, mirroring those TF formations being sent overseas. The titles of these 2nd Line units would be the same as the original, but distinguished by a '2/' prefix. In this way the 1/I and 2/I Home Counties Brigades were formed. On the outbreak of war in August 1914 the unit was under the command of Lt-Col Sir Berry Cusack-Smith, 5th Bt, KCMG, former Consul-General to Valparaiso, and the officer commanding 1st Sussex Bty was Major A.P. Boxall (nephew of Sir Charles Boxall). 1/I Home Counties Brigade The bulk of the Home Counties Division, including the 1/I Home Counties Brigade without its Brigade Ammunition Column, embarked at Southampton and sailed on 30 October 1914 for India to relieve Regular Army units to fight on the Western Front. The Territorials disembarked at Bombay 1–3 December, and were allotted to various peacetime stations across India. Although the Home Counties Division remained in the order of battle and received a number (as