Mobilisation During the period of tension before the outbreak of war, the 9th Battalion sent two special service sections to guard a cable station at Cuckmere Haven and Birling Gap (28 July). When the mobilisation orders were received on 4 August 1914, the Home Counties Division was on the march from
Aldershot to
Salisbury Plain for its annual training. The Middlesex Brigade had reached
Larkhill, when the battalions were sent back to their headquarters to mobilise. The 9th Battalion entrained at Amesbury on 5 August and reached Willesden that morning. By the end of the day the battalion was entrained again for its war station at Sheerness. Here it dug trenches for a few days until relieved by
Special Reserve troops and moved to
Sittingbourne. On 11 August, in common with the majority of the men of the Home Counties Division, the 9th Battalion accepted liability for overseas service. The Home Service-only and under-age men, together with the recruits who were flooding in, remained at the depots to form 2nd-Line battalions. The titles of these 2nd Line units were the same as the original 1st Line, but the two would be distinguished by '1/' and '2/' prefixes. The 2/9th Bn formed on 18 September; subsequently, a 3/9th Battalion was formed to provide drafts to the other battalions.
1/9th Battalion India In October 1914, the Home Counties Division was ordered to
India to relieve Regular troops there. The 1/9th Middlesex embarked at Southampton on 29 October in the transports
Dilwara and
Dongola, and disembarked at
Bombay on 2 December. On arrival, the Home Counties Division was split up and the battalions were distributed to stations all over India. For the next three years they acted as a peacetime garrison, while suffering a steady drain of their best men to officer training and other duties. 1/9th Middlesex was assigned to the
Presidency Brigade in
8th (Lucknow) Division, based around
Calcutta. The main body was stationed at
Dinapur, with E, F and H Companies detached to guard the arsenal at
Dum Dum; later D and F Companies went to garrison
Barrackpore, where they were responsible for guarding the
Rifle Factory Ishapore and the
Cossipore gun and shell factory. When the four-company system was adopted in May 1915, the companies at Dinapur provided A and B Companies together with the battalion scouts and machine-gunners, those at Barrackpore became C Company, and those Dum Dum became D Company and the signallers. In May and August 1915, the battalion supplied its first drafts to the 2nd Bn
Norfolk Regiment serving in
Indian Expeditionary Force D in
Mesopotamia; of the 50 other ranks sent, 20 died at the
Siege of Kut or in captivity afterwards. In January 1916, the battalion was transferred to the
5th (Jhelum) Brigade,
2nd (Rawalpindi) Division, on the
North West Frontier. On arrival at Rawalpindi, it was ordered to mobilise for service with Force D. However, the order was quickly cancelled, and for the next two years the battalion continued to train. During this period, it was constantly moving station: • March–April 1916 to
Nowshera Brigade,
1st (Peshawar) Division, for mountain warfare training; • April–June to
Murree; • June–November to Galis Brigade, with one company detached to guard
Attock Fort; • November returned to Jhelum Brigade • February 1917 to
43rd Indian Brigade in
16th Indian Division, a reserve division for the North West Frontier • March 1917 to
Ambala Brigade in
3rd Lahore Divisional Area (the
3rd (Lahore) Division being absent, serving in Mesopotamia). Here, the battalion received a large draft from the 7th Reserve Battalion (
see below) and from the
Essex Regiment, which partly restored its strength after years of losing men to sickness and supplying so many drafts and specialists. From November 1917, the battalion reverted to the title of 9th Middlesex when the 2/9th Bn disbanded in England (
see below).
Mesopotamia In October 1917, the 9th Bn was selected to be the British battalion in a new
53rd Indian Brigade being sent to the
Mesopotamian Front. On 5 November it was brought up to full strength with drafts of 100 menfrom the 1/10th Middlesex and 200 from the
1/25th London Regiment. The men from 1/25th Londons, formerly a
bicycle battalion, were disappointed at being spread across all 16 platoons of the 1/9th rather than being kept together as a distinct company. The battalion embarked on the transport
Egra at
Karachi on 19 November. It landed at
Basra on 23 November and the brigade became part of
18th Indian Division at
Baghdad on 24 December. The division was not concentrated until mid-March 1918, and when it moved north up the
Tigris, 53rd Brigade was left behind to subdue
Nejef, south of Baghdad. After making a forced march of nearly 90 miles in a week through almost waterless country and carried out a demonstration, the brigade was being withdrawn when trouble flared up again. The town was then blockaded from 21 March to 19 May, with the 9th Middlesex being involved in minor actions. The battalion celebrated
Albuera Day in the Mesopotamian desert. 53rd Brigade then rejoined the division at Akab, near
Samarra. Summer weather made campaigning impractical in Mesopotamia, so the division was engaged in roadbuilding until the beginning of October, when orders were received to join the renewed advance up the Tigris. 9th Middlesex moved up to
Tikrit on 10 October, arriving on 14 October, with many men suffering from sickness. The division began its attack (the
Battle of Sharqat) on 24 October, with 53rd Brigade in support. The brigade passed through the Fathah Gorge and the following day pushed on under artillery and machine-gun fire to establish a bridgehead over the
Little Zab. Between 11.00 on 25 October and 17.00 on 26 October, the infantry covered . On 26 October, the brigade patrolled forward up the left bank of the Tigris and the right bank of the Little Zab, and demonstrated towards Humr Bridge, to make the Turks think that a crossing was planned. That the night the Turks began to retreat and on 27 October, 53rd Brigade began a pursuit march, delayed only by Turkish artillery fire. The Turkish force surrendered on the evening of 29 October, when 9th Middlesex was about to support an attack on the opposite bank of the Tigris. 18th Indian Division pushed a flying column on to capture Mosul, while the infantry retired towards its railhead at
Baiji for supplies. After the
Armistice of Mudros came into effect on 31 October, the division began preparing for the postwar occupation of Iraq as the Turks withdrew.
Demobilisation began in early 1919, but on 23 May the battalion (now reduced to three companies) was ordered to join a punitive column marching into
Kurdistan. The column was in contact with insurgents from 28 May to 18 June when the rebel leader was wounded and captured. While 'mopping up' after the formal surrender, two companies of the 9th Middlesex and two squadrons of Indian cavalry found themselves surrounded near
Kirkuk. They were pinned down for three days under heavy rifle fire, with rations being dropped to them by the
Royal Air Force, before being relieved. The battalion was demobilised on 11 September 1919. Late in 1915, 201st Brigade moved to
Sevenoaks, later camping at
Barham. The 67th Division had dual responsibility as part of the mobile force for Home Defence, and to train drafts for overseas service. Twice it was ordered to prepare for service in Ireland, and in April 1917 it prepared to go to France. However, nothing came of these deployments, and the division was drained of its manpower as its men were drafted to frontline units. The 2/9th Middlesex was disbanded on 14 November 1917 at
Patrixbourne in Kent. ==Interwar==