Source: Operation Sea Lion: GERMAN PLANS FOR THE INVASION OF ENGLAND 1939-1942 by Ronald Wheatley

OKH OPERATIONAL INSTRUCTION FOR SEA LION, 30 AUGUST 1940

The Commander-in-Chief of the Army H.Q. OKH, 30 August 1940
General Staff/Operations Branch (Ia)
               No. 480/40 g. Kdos.

Instruction for the Preparation of Operation Sea Lion

1. Task

The Supreme Commander has ordered the Services to make preparations for a landing in force in England. The aim of this attack is to eliminate the Mother Country as a base for continuing the war against Germany, and, if it should be necessary, to carry out a complete occupation.

The order for execution depends on the political situation. Preparations are to be made in such a way that the operation can be carried out from 15 September.

While continuing with its occupation duties in France and maintaining the security of the other fronts, the task of the Army will be to land strong forces in southern England, defeat the British Army, and seize the capital. Other areas of Britain will be occupied as opportunity permits.

2. Code word

The operation will bear the code name ' Sea Lion '.

3. The course which the operation will take is dependent on a number of unpredictable circumstances. Therefore preparations for embarkation, crossing, and initial landing must be flexibly made, so that the High Command can meet unforeseen alterations in the situation without loss of time. Commanders and troops must realize that the peculiar conditions of sea transport render the disintegration of formations unavoidable and that unusual situations will crop up which can only be mastered by very great initiative on the part of all commanders.

4. Proposed method of execution

(a) The Luftwaffe will destroy the British Air Force and the armament production which supports it, and it will achieve air superiority. The Navy will provide mine-free corridors and, supported by the Luftwaffe, will bar the flanks of the crossing-sector.

(b) The Army's landing forces will first win local bridgeheads with the specially equipped forward echelons of the first-wave divisions. Immediately afterwards, they will widen these bridgeheads into a connected landing-zone, the possession of which will cover the disembarkation of the following troops and ensure early uniform control on the English shore. As soon as sufficient forces are available, an offensive will be launched towards the first operational objective, i.e. Thames estuary-heights south of London-Portsmouth. As the British will make counter-attacks against the German troops who have landed first, and as they will resist with every means further German gains in terrain, bitter fighting is to be expected. Command and organization of troops must be equal to the decisive significance of these initial actions.

(c) After gaining the first operational objective, the further task of the Army will be as follows : to defeat the enemy forces still holding out in southern England, to occupy London, to mop up the enemy in southern England, and to win the general line Maldon (north-east of London)-Severn estuary.

Orders concerning further tasks will be issued at the proper time.

(d) The current enemy situation, as before, will be periodically forwarded to army groups and armies.

5. Command and organization of forces

At first, Army Group A (with 16th and 9th Armies) will be entrusted with the execution of the tasks allocated to the Army. Whether elements of Army Group B will also be employed as operations proceed depends on the development of the situation.

For order-of-battle of forces allotted for Operation ' Sea Lion ', see Appendix 1.

The former tasks of the army groups (coastal defence, occupation duties, security of the Demarcation Line) remain in force.

6. Tasks of army groups and armies

(a) Army Group A 's task. Starting on orders from OKH, the Army Group will force a landing on the English coast between Folkestone and Worthing; and it will, first, take possession of a beachhead, where the landing of further forces, aided by artillery fire in the direction of the sea, can be ensured and where it will be possible to create the preliminary conditions for continuing the attack. Early utilization of dock installations on the enemy coast is desirable for the rapid disembarkation of following forces.

After the arrival of sufficient forces on English soil, the Army Group will attack and secure possession of the line Thames estuary-heights south of London-Portsmouth. As soon as the situation permits, mobile formations will be pushed forward to the area west of London in order to isolate it from the south and west and to capture crossings over the Thames for an advance in the direction of Watford-Swindon.

(b) Initial tasks of armies. 16th Army will embark in the invasion ports situated between Rotterdam (incl.) and Calais (incl.). [Translator's note: incl. = inclusive.]

Landing on a broad front on the Folkestone-Hastings (incl.) section of coast, the Army will occupy an area at least as far as the line: heights halfway between Canterbury and Folkestone-Ashford-heights 20 km. north of Hastings. Speedy capture of the dock installations at Dover is important. The Ramsgate-Deal section of coast, which, for naval reasons, can only be approached when the coastal defence is eliminated, must be taken from the landward side as soon as possible.

Arrangements will be made to use paratroops for the speedy capture of the high ground north of Dover: this operation will take place at the same time as the landing. 9th Army, landing simultaneously with 16th Army between Bexhill and Worthing, will occupy a beachhead at least up to the line: heights 20 km. north of Bexhill to heights 10 km. north of Worthing. It must be realized that only the first echelons of three first-wave divisions can be shipped across the Channel for the Army direct from Le Havre; the fourth division and the later echelons and waves, starting from Boulogne, must cross under the screen cover of 16th Army's better-protected crossing-sectors, and must be disembarked east or west of Eastbourne as the situation dictates.

The use of paratroop units for the capture of Brighton will be arranged.

Boundary line between 16th and 9th Armies : Boulogne (9)-Hastings (9)-Reigate (16).

[On 21 Sept. 1940, OKH released an amendment to 9th Army's Task – it reads as follows:

9th Army, landing simultaneously with 16th Army between Bexhill and Brighton, will occupy a beachhead at least up to the line: heights 20 km. NW. of Bexhill-Uckfield-heights west and south-west of Lewes. It must be realized that only the first echelons of three first-wave divisions can be shipped across the Channel for the Army direct from Le Havre; the remaining echelons and waves, starting from Boulogne, must cross under the screen cover of 16th Army's better-protected crossing-sectors and must be disembarked east or west of Eastbourne as the situation dictates.

Boundary line between 16th and 9th Armies: Boulogne (9)-Hastings (16)-Reigate (16).]

Separate orders will be issued regarding the time of landing on the English coast. The intention is to land at daybreak. Dependence on weather and tides, however, may necessitate a landing in broad daylight. In this case, extensive use of smoke is ordered (with the aid of aircraft, vessels, and artillery).

(c) Army Group B's task. [Replaced by Army Group C as from 11 Sept.]

Army Group B will not participate in the initial phase of the operation. If the naval situation develops favourably, the Army Group, starting from Cherbourg, may be employed later to force an air and sea landing in Lyme Bay, and to occupy, first, Weymouth and the high ground 20 km. north of Weymouth-15 km. north of Lyme Regis. From here, an advance would, on instructions from OKH, be made in the direction of Bristol. later, elements of Army Group B may receive the task of occupying the counties of Devonshire and Cornwall.

Army Group B will, in conjunction with the naval authorities, decide on embarkation ports and determine their capacity. Its landing troops will be assembled in readiness, so that, on orders from OKH, they can be brought up for embarkation within five days. The following instructions for assembly and organization of forces, which primarily concern Army Group A, are also valid, where applicable, for Army Group B.

7. Organization of forces

Detailed organization will be determined by army groups and armies to suit their various embarkation areas and their initial tasks on English soil.

Apart from the separate instructions already issued on this subject, the following points should be observed.

(a) The composition of the first echelon of the first wave, as laid down in OKH Organization Branch Instruction No. 1084/40 g. Kdos. dated 20.7.40, is only a suggestion. Men and weapons should be ferried across as rapidly and in as large numbers as possible without paying scrupulous attention to organic cohesion. The essential point is to form battle groups in accordance with the task to be carried out.

(b) Units of panzer and mobile formations, especially U-tanks, will be included early in the landing echelons.

(c) Arrangements must be made to send on troops of medium artillery for use as coastal artillery on the far shore, so that the stretches Calais-Deal and Boulogne-Hastings are covered as early as possible by artillery on both coasts (Artillery Commander 106's Group, and, later, 1st Battery/84th Artillery Regiment). For use of Flak units, see Appendix 3 [not included].

(d) Engineers' tasks

(aa) Support of troops during embarkation, especially when taking place outside ports.

(bb) Support during the initial landing on a broad front (assault boats, motor-boats, pneumatic boats).

(cc) Support during disembarkation of men, vehicles, and horses from transports, especially on open coasts.

(dd) Provision of assistance to the troops first landed during removal of shore obstacles, especially mines ; support of infantry as the attack continues.

(ee) Assembly of the forces and equipment required to support the troops defending the bridgeheads gained.

The forces used for tasks (aa) and (cc) will in general remain where they are as static units, in order that the embarkation and disembarkation of later waves may be carried out under the control of special staffs.

(e) Special measures to provide a curtain of fire against land targets during the landing will be vigorously improvised by all commands in accordance with the pamphlets, etc., issued.

(f) Each landing unit in the foremost echelons must be so organized that, after the landing has taken place, it is suited for independent combat tasks even on the smallest scale. The commanders of all units will accompany their front-line troops.

(g) Loading of shipping space for the second and subsequent journeys cannot be rigidly determined in advance. By means of an organization working closely with the naval commands, it must be possible to arrange loading of the available shipping quickly and flexibly in every case. To this end the establishment of a reliable signal network is indispensable.

(h) As far as the transport situation permits, the requirements of the Deputy Quartermaster-General—England (O. Qu. England) must be borne in mind by the armies in determining priorities. (See Appendix 4) [not included here].

7. [sic] Assembly of forces

(a) First wave. Forces destined for the first wave will be assembled near the embarkation ports prepared by the Navy.

These 'embarkation ports' are:

for 16th Army: Rotterdam
                       Antwerp
                       Ostend
                       Dunkirk
                       Calais

for 9th Army: Boulogne
                       Le Havre (the latter only for the first echelons of three divisions).

Nieuport and Gravelines will serve as 'auxillary ports' (which are not to be used for embarkation purposes).

Further embarkation on the open coast, in river mouths, or in small harbours will be possible only to a modest extent.

Details of place, type, and sequence of initial loading will be fixed immediately by the armies ('Liaison Officers') with the competent naval authorities (who have received instructions).

[There are Naval Headquarters (Kriegsmarinedienststellen) at Rotterdam, Ostend-Dunkirk, Calais, Boulogne, and Le Havre. In other harbours, there are Naval Officers i/c Ports (Hafenkommandanten) or Port Captains (Hafenkapitäne).]

It must be axiomatic that as much equipment as possible (including supplies) is loaded beforehand, as the time taken to embark troops and horses must, when it finally takes place, be cut down to a minimum.

To procure, equip, and assemble transportation is the task of the Navy and will be regulated by speclal instructions from the Naval (War) Staff.

It is the troops' responsibility to arm barges and even tugs with weapons of all kinds, in so far as the naval authorities have not already done this : this task will be carried out on an extensive scale in accordance with the pamphlets issued. The curtain of fire from the sea covering the landing troops will be supplemented by the guns of armed naval vessels (mine-sweepers, &c).

(b) Second wave. At the proper time armies will move up, by road, the mobile formations destined to cross with, or following, the first wave, and will assemble them in the area of the embarkation ports. Rotterdam and Antwerp can be considered for use as loading points by 16th Army, Boulogne by 9th Army. Preparations to bring up these forces must be so arranged that from 15 September onwards they can be assembled within three days. Corps, divisions, and regiments of mobile formations allocated to 16th and 9th Armies are immediately placed under command of both armies for these preparatory tasks.

(c) Third wave. The third-wave formations which are not provided with railway transport will be moved forward near the coast by early morning on 15 September. Where and when it will be possible to ship them will not be known at first. Their grouping must therefore be such as to enable their forward elements to reach the most suitable army ports in three moves.

With regard to the formations which OKH will bring up by rail (see Appendix 1) [not included], Army Group A will report desired time of arrival and detraining area.

(d) Fourth wave. The OKH Reserves will, at first, remain in their previous areas and will be moved up as required by OKH.

(e) During the approach and assembly of forces belonging to all waves, care must be taken to avoid unnecessary crowding; provision of the A.A. defence required must be ensured in conjunction with the competent Luftflotten [Air Fleet] H.Q.s.

8. Luftwaffe operations

(a) Operational Luftwaffe—see Appendix 3.

(b) Army Air Formations—see Appendix 3.

9. Security

Preparations for the landing planned require especial secrecy. The fact that a landing in England is being prepared cannot be concealed. It is thus all the more important to use every means to keep the time of the proposed landing and [the location of] the crossing-sectors secret.

10. Deception measures

Measures have been introduced to give the appearance of a projected landing on the east coast of England and in Ireland. Details have been passed to the commands concerned.

11. Reports

Army Group A is requested to furnish the following information by 3 September:

(a) Intended approach and assembly of the first wave (Map). Use of paratroops, etc.

(b) Intended assembly of the second wave (Map).

(c) Intended battle H.Q.s of Corps H.Q.s and below.

(d) Estimate of the probable time required for ferrying across the individual echelons and waves (in conjunction with the naval authorities).

(e) Requested time of arrival and detraining area for the third-wave divisions which will move up by rail.

(f) Time of day proposed for landing.

(g) Suggestions and proposals.

(Signed) VON BRAUCHITSCH