The Defence scheme in place for the United Kingdom on the outbreak of war was along the lines of pre-war thinking – i.e. the Navy would discover and destroy any invasion force greater than 70,000 men while the Territorial Force would be sufficient to deal with any force up to 70,000.
The primary duty of the Navy was still to maintain a force that could overcome any politically probable combination of hostile forces. Such a policy required the Navy to control all seas necessary to the Imperial interests, and to meet and defeat any enemy force wherever and whenever it was accessible to attack. For such an offensive role it was impossible for the Navy to tie up part of the fleet in a passive defence role. Such a freedom of manoeuvre made it possible for a hostile force to be landed in the United Kingdom without being detected. Such a hostile force may be landed with the intention of invasion (by which the enemy would seek to obtain a decisive result) or a raid (by which the enemy sought to seek a blow against Britain’s naval and military power or to influence operations elsewhere).
The general principal for Home Defence was to maintain an army at home that could repel small raids and also would be of sufficient size to compel the enemy in any invasion attempt to send such a force that would make it impossible to evade the Navy. Such a force was considered not likely to exceed 70,000 men lightly equipped with transport and artillery.
Any invasion force would have a limited time to achieve its objective before its communications were cut by the Navy (unless of course the Navy had lost control of the seas). In order to do this it would have to rely on the ammunition and supplies brought with it. The only realistic objective would be to force the surrender of the British Government by a direct attack on London – this required the invasion force to be landed within a few days march of London. As a raid could not force a decisive result, it was considered the enemy would send the minimum force required to complete the task; this was not expected to be greater than 10,000 men accompanied by light artillery. The objective of raids could be against fixed defences of Defended Ports, to create panic and prevent troops from being despatched to France or destroy wireless stations.
The land forces to deal with the threat of invasion and raids, after the Expeditionary Force had been despatched were:
A main army, referred to as Central Force, to defeat an invasion and support Local Forces. Central Force was comprised of three Armies, 1st, 2nd and 3rd Armies. A Mounted Division, concentrated in East Anglia also formed part of Central Force.
Local Forces to assist the garrisons of Defended Ports and repel raids and to reinforce Central Force.
Garrisons to defend places of commercial and naval importance i.e. Defended Ports. Defended Ports had also been provided with fixed defences.
Detachments to guard vulnerable points and to aid the Civil powers in maintaining order in London.
Above and right: War Stations of Home Forces in Suffolk Aug 1914 and Defended Ports
Central Force was to be composed of any regular troops left over after the despatch of the Expeditionary Force as well as Reserve and Territorial Troops. Prior to mobilization, troops were under the command of the Commander-in-Chief of the Command area they were stationed in. Central Force was to be at War Stations within 14 days of mobilization, when they would then come under the command of the Commander-in-Chief Central Force, to ensure that they could bring any invading force to action before it reached London. Central Force HQ at War Stations was located at Horse Guards, London.
The Mounted troops, which included attached Cyclist battalions, were stationed along the East Anglian and South East coast lines. Their role was coast watching and to repel raids against parts of the coast not guarded by Local Forces. Mounted Infantry had the ability to move rapidly and cover long distances in a relatively short time, meaning they could be rapidly moved to any part of the coast under attack. Cyclists performed a similar role and were especially useful in enclosed country where roads were numerous and good. They could traverse longer distances and move faster than horseman in such country. They were stationed at locations with good rail connections to further increase their mobility.
Local Forces were comprised of Territorial troops and had been organised in the Commands (London District, Scottish, Northern, Western, Southern, Eastern and Irish) to assist garrisons of Defended Ports and meeting raids. Local Forces were distributed with regards to the importance of the objectives to be guarded and the probability of attack on these objectives. The possibility of feint attacks had been taken into account. In the case of a serious attack, Local Forces would be reinforced by Central Force.
The duty of Garrisons was to hold the Defended Port until such time as relieved by Local Forces and an offensive against the raiders could be mounted. The size of the Garrison was determined and fixed by factors such as importance of the objective, the time required to hold before Local Forces or Central Force could intervene, topography of likely landing places etc.
Fixed defences at Defend Ports were calculated to deter an enemy from risking ships to bombard the port and were not intended to meet prolonged operations. It was calculated that the Navy would be able to intervene within 48 hours at even the remotest port.
It was considered that the enemy would generally not waste time in attacking Defended Ports in any invasion attempt as time would be a decisive factor. However the enemy would probably contemplate the capture of a port such as Grimsby or Harwich in order to disembark heavy equipment and stores.
In order to bring a decisive decision by invasion, London would be the target and the enemy would unlikely select a location for disembarkation further from London than he was required to. The coast between Selsea Bill and the Humber was then considered to be most at risk. If the enemy chose a location on the south coast, he would run a greater risk in passing through the Straights of Dover into narrow waters than in if operations were limited to the North Sea. The Thames and Medway were considered unlikely locations for disembarkation due to the presence of torpedo boats and submarines.
Topography was also considered of importance for the selection of a disembarkation location by the enemy. The Fens were difficult country for military operations and would form a useful flank protection for any landings in Lincolnshire or Norfolk. In Suffolk and Essex the rivers Orwell, Stour, Blackwater and Crouch all formed difficult obstacles to cross. South of the Thames, Romney, Welland and Dunce Marshes were considered impassable except for infantry moving in small groups. The Rivers Cuckmere, Ouse, Adur and Arun were also serious obstacles for some miles inland. The Medway was also a serious obstacle but not above Rochester.
Taking all these factors into account the most likely area to be selected by the enemy for invasion was between the Humber and River Thames. Harwich was considered to be a likely target to assist in unloading stores and equipment.
The location in which Central Force was to be concentrated on mobilization was governed by the above considerations. There were two options:
To concentrate on the enemy’s likely flank, with the advantages of secure communications while threatening the enemy’s and forcing the enemy to break of his attack on London or be exposed to attacks from his flank and rear.
To concentrate in an area between the likely disembarkation points of the enemy and London with the advantage of a greater feeling of a sense of security for London and forcing the enemy to continually advance through hostile country. The flanks of such a position would be relatively secure as the Thames would guard one flank while a substantial detour would have to be taken by the enemy to turn the other flank.
Due to Territorial Forces not having sufficient training in rapid manoeuvre and political considerations the latter option was chosen for the concentration of Central Force. Once the field of operations had been selected, the following were important considerations for the actual War Stations of Central Force:
Good communications, especially rail
Sufficient accommodation to billet troops
Suitable training facilities
The area chosen to concentrate the main body of Central Force (1st and 3rd Armies), the result of a reconnaissance carried out before war was declared, was in the following area:
Cambridge-Huntingdon-Wellingborough-Northampton-Leighton Buzzard-Luton-St Albans-Brentwood-Bishop’s Stortford with a mounted brigade at Colchester.
Such an area provided excellent rail links to transport troops to meet either a landing along the Lincolnshire coast or Sussex/Kent coast. A landing along the Norfolk/Suffolk/Essex coasts was more problematical as the rail links were not as good and often single track in places. However the concentration area was sufficiently close to mean that rail moves required would be few.
The 2nd Army was to be retained in the Aldershot area where it could easily be railed to the main concentration area if operations took place in East Anglia or form the advanced guard to the main force if landings took place south of the Thames. The Mounted Division was to concentrate in the area Diss-Bury St Edmunds-Ipswich.
If invasion took place, as has already been stated, all forces within the area of operations would come under the command of the Commander-in-Chief Central Forces. Forces outside the invasion area would remain under the direct command of the Army Council. All reinforcing troops coming into the area of operations would come under the control of Commander-in-Chief Central Force.
The following towns were the principal concentration points for Central Force:
Cambridge – allotted to the South Wales Mounted Brigade. Cambridge was a vital entraining/detraining station. Although Cambridge only had one station, the London and North-Western , Midland, Great Northern and Great Eastern Railways had access to it; the Great Northern and Great Eastern had direct access to London from Cambridge.
Huntingdon and Godmanchester – allotted to Highland Mounted Brigade.
Bedford – allotted to HQ 1st Army, the Highland Division and other troops.
Northampton – allotted to the Welsh Division. Although not a vital rail centre, Northampton did have plenty of station accommodation in the way of platforms and sidings and did connect to the London-North Western railway system at Hardingstone Junction.
Wellingborough – allotted to the West Riding Division.
The 1st South Western Mounted Brigade and the 1st London Division were allotted to Aldershot, to be reinforced later with a second division.
Bishops Stortford – allotted to the North Midland Mounted Brigade. This was the most important stopping station between Cambridge and London.
Luton and Dunstable and surrounding towns– allotted to HQ 3rd Army and the North Midland Division.
Bury St Edmunds – HQ of Mounted Division
Ipswich – allocated to Eastern Mounted Brigade
Diss- allocated to Nottinghamshire and Derbyshire Mounted Brigade
Warwick - allocated to 1st South Midland Mounted Brigade
Reading – allocated to 2nd South Midland Mounted Brigade
As well as allotting areas for concentration of Central Force, arrangements were also in place for storage and delivering of supplies and ordnance, provision of engineering services (including a list of recommend local firms that could be contracted), provision of medical services (using existing Military hospitals, Territorial general hospitals and temporary hospitals to be improvised as required), the supply of horses and veterinary services and facilities for training. The Force was to be largely billeted in buildings (e.g. schools, farm barns, hotels etc) in surrounding villages. Estimates had also been drawn up of further supplies that could be requisitioned in the area of operations; for example in Norfolk this included 22,500 horses, 11,000 cows (excluding those in calf), 39,300 cattle other than cows, 190,000 sheep and ewes and 45,000 pigs which were estimated to be within 25 miles of the coast.