The 5th Battalion Royal Sussex Regiment (Cinque Ports) was formed on 1st April 1908 as part of the newly constituted Territorial Force.
The new force of volunteers was organized as follows:
A - Company at Hastings (depots at Eastbourne and Hailsham)
B - Company at Battle (depotts at Dallington, Sedlescombe, Staplecross, Robertsbridge and Bexhill)
C - Company at Wadhurst (depots at Burwash, Flimwell, Hurst Green, Ticehurst and Frant)
D - Company at Lewes (depots at Glynde and Stanmer)
E - Company at Rye (depots at Icklesham, Winchelsea, Peasmarch and Northiam)
F - Company at Uckfield (depots at East Hoathly, Hadlow Down, Nutley, Buxted, Newick and Heathfield)
G - Company at Crowborough (depots at Blackham, Hartfield, Groombridge, Mayfield and Rotherfield)
H - Company at Ore (depot at Westfield)
In 1914 the 1/5th were also re-organized into four companies as follows:
A - (Hastings) & E (Rye) became A Company
B - (Battle) & F (Uckfield) became B Company
C - (Ticehurst) & D (Lewes) became C Company
G - (Crowborough) & H (Ore) became D Company
The original battalion was thereafter known as the 1/5th, with two reserve units formed later - the 2/5th and 3/5th. These supplied drafts to the 1/5th Bn in France, and later personnel to several battalions of the regiment.
It first posting came in early 1915 when it was called for duty at the Tower of London. Around this time several composite battalions of the Cinque Ports were formed.
On 18th February 1915 the battalion crossed to France on SS 'Pancras' and landed at Boulogne. Their first action in 1915 as part of the 2nd Brigade, 1st Division was at the Battle of Aubers Ridge on May 9th. The 2nd Battalion Royal Sussex Regiment was also serving in the 2nd Brigade and they fought side by side.
On the 20th August 1915 it was transferred and became the Pioneer Battalion of the 48th (South Midland) Division. The New ‘Sussex Pioneer’ Battalion joined its new division on the Somme at Heruterne.
(The British 48th (South Midland) Division was a Territorial Force division. Originally called the 'South Midland Division', it was redesignated as the 48th Division in 1915.
143rd Brigade (Warwickshire)
1/5th Battalion, The Royal Warwickshire Regiment
1/6th Battalion, The Royal Warwickshire Regiment
1/7th Battalion, The Royal Warwickshire Regiment
1/8th Battalion, The Royal Warwickshire Regiment (until September 1918)
144th Brigade (Gloucester and Worcester)
1/4th (City of Bristol) Battalion, The Gloucestershire Regiment
1/6th Battalion, The Gloucestershire Regiment
1/7th Battalion, The Worcestershire Regiment
1/8th Battalion, The Worcestershire Regiment (until September 1918)
145th Brigade (South Midland)
1/5th Battalion, The Gloucestershire Regiment (until September 1918)
1/4th Battalion, The Oxfordshire and Buckinghamshire Light Infantry
1/1st Buckinghamshire Battalion, The Oxfordshire and Buckinghamshire Light Infantry
1/4th Battalion, Princess Charlotte of Wales's (Royal Berkshire Regiment)
1/5th (Cinque Ports) Battalion, The Royal Sussex Regiment)
(Pioneer battalions : - Although they had existed in the Indian Army before 1914, pioneer battalions were essentially an innovation of the British Army during the First World War. During the war there was a much heavier reliance on field work and roads and railways needed to be maintained. Engineers alone could not meet the heavy demand, while rifle men were always needed at the front. Therefore, pioneer battalions were raised to meet the needs of both and trained to support engineers and infantry.)
The 48th Division fought on the Somme at the Battle of Bazentin Ridge (15th-17th July), the Capture of Ovillers (17th July), next to the 1st Australian Division at the Battle of Poziers Ridge (23rd – 27th July), The Battle od Ancre Heights (3rd – 11th November) and Battle of Ancre (13th – 18th November).
In 1917 the Pioneers were fighting at the Hindenburg Line (14th – 5th April), Peronne (18th March) and at the Third Battle of Ypres: Langemarck (16th -18th August), Polygon Wood (28th September – 3rd October), Broodseinde (4th October) and Poelcapelle (9th October).
In November 1917 the battalion went with the division to Italy, and in November 1918 was in Austria, east of Trent. It returned to England in 1919.
For more information:
Royal Sussex Regiment - 5th Battalion.
Regiments.org - 5th Battalion.
The Long, Long Trail - 48th Division.
Pioneer Battalions - The Long, long Trail.
Australian Pioneer Battalions.