Fort Gilkicker



1779 Invasion Plans

by Rob Harper: Conservation Officer Gosport Borough Council

1779 Invasion Plans, forces, defensive preparations in the Portsmouth/Gosport area, and chronology of events.
Several plans were considered by the French between 1768 and 1779.

1768: Choiseul produced the ‘Portsmouth Project’
One part: Disembark on the west Sussex coast between Littlehampton and the mouth of the Chichester Channel, split the invading army in two: one part advancing inland as far as Guildford and Dorking, and the other west to occupy Portsdown Hill. The Portsea lines should then be immediately attacked (consisting of two feeble entrenchements either side of the northern edge of the Island).
Other part: Try to thrust small craft through the Hayling Channel in order to take Portsea Lines from the rear, enter Spithead, bombard Fort Cumberland and Southsea Castle, and land more troops on the shore beyond Gosport, which place should be easily carries by assault.
Once the French were masters of Portsmouth they could capture the Isle of Wight (which might even be retained at the conclusion of peace). All troops who could be spared would then head back through Petersfield and Farnham in order to come into line with the troops in Guildford and Dorking. The whole force would then resume its advance and after a battle (which by then must have been expected) it would secure the crossings of the Thames above London at Putney, Kew, Kingston and Hampton Court. It would then proceed to occupy the heights of Hampstead and Highgate, after which the capital would be cut off from the country and be at the mercy of the French Army.

Comte de la Luzerne Plan 1778:
He stated that through temporary naval superiority 60,000 troops could be landed at or near Shoreham in Sussex. The army, once landed, would be split into three parts: 10,000men would advance into Kent, take Chatham, and burn the dockyard if forced to evacuate. 15,000 should advance to threaten London occupying Woolwich and Deptford, where all shipyards, magazines, and vessels in the stocks must be burnt. London itself need not be entered in force, though a detachment should be sent in to burn the arms and artillery in the Tower of London and to levy a contribution.
 Meanwhile the main body should march to capture Portsmouth from the landward side, together with Gosport and the Isle of Wight. Afterwards, leaving a strong garrison, the remainder of this division should re-join the other two forces in order to force the line of the Thames and drive the British back into the north of England, or even Scotland. Plymouth, as poorly defended on the landward side as Portsmouth, must either be taken by a detachment from the main army or by fresh troops from France landed at Dartmouth. The contributions which would be levied elsewhere would serve to fortify Portsmouth.

Plan of Robert Mitchell Hamilton, a renegade British naval officer. 20th March 1779.
He claimed Portsmouth and Gosport only had a garrison of 1,000 men. It would be possible, he believed, to surprise Spithead and once the French were masters of the roadstead, they could land both in the Isle of Wight and on the mainland at Stokes Bay, and bombard or attack Portsmouth and its dockyard from the Gosport side.

Plan of  De la Roziere 1779 (First Official Plan)
Absolute control of the sea would be necessary as a preliminary to the ‘expedition against Portsmouth’. As soon as the combined fleet had established control light vessels would be detached to escort the transports carrying the army of invasion. This army would not be more than 20,000 strong: all infantry, except for a few hundred dragoons.
An attack on the Isle of Wight would be made, followed by one on Gosport, from which Portsmouth and its dockyard could be bombarded and destroyed.

Plan of La Rousseliere May 1779
After the British Fleet had been got out of the way, the Isle of Wight must then be taken.  The landing, for which 4,000 troops would be required, should be made on both sides of the Cowes River, and the troops should immediately march on Newport.  The island’s capture should be over in a single day. Gosport must be attacked simultaneously by a force of 6-8,000 men landed in Southampton Water under the protection of the escorting warships. When it had been captured the dockyard and lower part of the town of Portsmouth could be bombarded from across the harbour by at least 24 mortars.

La Rousseliere’s plan for the occupation and retention of Portsmouth.
This would require not less than 30,000 troops. After the capture of the Isle of Wight and Gosport, 20,000 men would be assembled in the former for an assault on Portsea Island itself. This should be made 2 hours before dawn. The first detachment, 5-6,000 strong, must penetrate using small boats into the channel dividing Portsea Island from Hayling Island, in order to land and take the Lines in the rear. This would involve passing within range of Fort Cumberland and would be a perilous project but should be led by a daring commander and include the flower of the French Army (With covering fire from the line of Battle ships and bomb-ketches).
Then, 4,000men from the force which had taken Gosport would make a night attack across the harbour, cut the communications between Portsmouth and its dockyard, and march to join the division attacking the Lines, or create a diversion to aid it. The boats which had brought the division from the Isle of Wight would then return to pick up reinforcements which would enable the siege of Portsmouth town to commence. This should be over in a week, so long as sufficient siege materials were available.

Plan following Conference between De Vaux, Maurepas, Vergennes, Sartine and Montbarrey. 12th June 1779.
Many of the details remained as with the above plan. This warships were first to beat down or silence the fire of Southsea Castle, Lumps Fort and Fort Cumberland. The attack on Portsea was to be made simultaneously with that on Gosport, (having first captured the Isle of Wight). Furthermore, instead of the whole of the troops of the first division attacking the channel between Portsea and Hayling Islands, only the right wing would do so. The centre and left of the division would meanwhile land at Eastney and Southsea beaches respectively. The task of the centre would be to contain Southsea Castle which the left cut the communication between it and the town. The right wing would include 3,500 of the 6,000men of the division and be led by the divisional commander, De Rochambeau, in person.

  • In 1779 the Portsmouth Command is believed to have comprised: CinC Lt-Gen Monckton: 3 militia reg’ts (including a fourth at Gosport), and 6 companies of the 41st Invalids, but only a few artillerymen.


Portsmouth area defence preparations
As the primary objective of the French, Portsmouth benefitted from the expertise of Lt-Gen Monckton (Governor of Portsmouth from 1778). He saw the danger of the enemy seizing the Isle of Wight and converting it into a magazine and advanced base; pointing out the urgent need of defending Stokes Bay, on which he declared that the safety of the dockyard depended, since a landing there would be followed by the storming Gosport and a bombardment or attack launched against the yard from across the harbour. He also stressed the vulnerability of Southsea beach and the dangerous possibility of an attack on it leading to the Portsea Lines being taken from the rear and turned. The four points of danger he emphasised were exactly those identified in the French plan of attack.


Map of 1778 Map of 1782 showing the early Fort Monckton
Map of 1778 Map of 1782 showing the early Fort Monckton


July 1779: Monckton noted the lack of works carried out in the area: Fort Cumberland’s works were still unprepared, Eastney and Lumps Batteries had not been improved since a year before, and had insufficient men to hold them; On the Gosport side, although new guns were being mounted at Fort Blockhouse, the Lines of Gosport itself were likewise still unrepaired, and even the quantity of fascines and palisades which Amhurst had ordered to be obtained a year before, had not yet been received in full.

The island as a whole Monckton regarded as naturally very strong and if the peasants were armed and provided with a few light and easily portable field pieces, the island would become very formidable. He’d been advised that there ought to be 3,000 between the ages of 17 and 50.
By 1st August: Fort Cumberland was being completed. The ditches at Eastney and Lumps batteries were being cleared, and the platforms made fit for service. At Fort Blockhouse palisades, gates, barriers and drawbridges were being repaired, and at Priddy’s Hard the fortifications had been strengthened by the mounting of 8 18lbrs. The Gosport Lines were being repaired, especially that part which in turn enfiladed those at Priddy’s Hard. Chevaux de fries were being made, and it was proposed to throw up fieldworks ‘on the beach of Southsea Common’.
On 20th and 21st August he wrote again. Due to the deficit of artillerymen he was proposing to take any men from any regiment in his area.
On 10th August the Isle of Wight only succeeded in getting a few old cannon mounted and setting up a few beacons.


The defences of Stokes Bay circa 1779
The defences of Stokes Bay circa 1779 with the first fort at Gilkicker which was replaced by Fort Monckton (plan by Rob Harper)

The first Fort at Gilkicker: This temporary fort consisted of an earth bank, six feet thick, supported by fascines (brushwood bundles used to strengthen trenches and ramparts). The magazine of this fort was reported to have been so conspicuous from the sea, that it was used as a sea mark in place of the one that was demolished.


Archer's proposal for the fort at Gilkicker c1779 A proposal for the the fort at Gilkicker 1782
Archer's proposal for the fort at Gilkicker c1779 A proposal for the the fort at Gilkicker 1782


The Army of Invasion
CinC: Comte de Vaux (Aged 74).
Av Gd: Maj-Gen Rochambeau. 5 Grenadier & Chasseur bns (approx 2,200) and Lauzan’s Legion (850)
1st Division Lt-Gen the Duc de Langeron. 3 Brigades: 14bns (7,000)
2nd Division Duc de Chatelet:  3 Brigades: 12bns (6,000)
3rd Division Lt-Gen de Lugeac: 3 Brigades: 12bns (6,000)
4th Division Duc d’Harcourt: 3 Brigades: 12bns (6,000) Including the Reg’t Royal-Comtois
4 Squadrons of Dragoons (400)
Hussar Regiment (400)
Siege Guns, and 106 Field Guns
Combined Total: 31,000 men
500 vessels had been prepared and assembled.

12th June: English Government hear that the French Fleet was out of Brest and at Sea. Spanish declare war.
9 June Rochembeau writes to Harcourt noting his command of 17 regiments and 300 dragoons . Felt the command should be split between Harcourt and Langeron with Harcourt commanding 34 battalions.
22nd: Spanish Fleet sails out of Cadiz
French fleet sailed to rendezvous with the Spanish, but the latter significantly delayed. In the first half of July smallpox and ‘putrid fever’ broke out amongst the French crews.
It was said at this time that the invasion force would only comprise 24-25,000 men.
2nd: 30 SOL (French) spotted off Ferrel
18th: 14 English ships, (including one believed to be of 50 cannon, four frigates of 26 to 30 guns, sloops, cutters and luggers) reported sailing off St Malo (near Chausey) to intercept all that appeared to be trying to enter (They were reported off St Malo on 20th, Cherbourg 22nd, Le Havre 24th: commanded by Governor Johnston of the Channel Islands.).
22nd -23rd:  Spanish Fleet eventually appeared. A week then spent practicing manoeuvres.
28th: Having terminated the embarkation of troops at St Malo De Vaux left for Le Havre.
Admiral Sir Charles Hardy had 36 SOL’s, 8 frigates, and a score of other smaller craft in early August. His crew totalled 26,544 men with 1,260 guns.
D’Orvillier’s had sailed with 28 SOL, 9 Frigates, many smaller craft with 27, 891 men and 3,014 guns.
1st: The French on land have had no news of D’Orvilliers for some days.
14th: 200 dragoons planned to be embarked with their horses and 50 on foot. De Vaux advises Harcourt that he had orders to head for St Malo and to leave Harcourt in command in Le Havre. Harcourt ordered to start embarkation of the troops. (One Division was planned to leave from St Malo and the other from Le Havre). De Vaux also mentions the troops encamped at Montevilliers, Harfleur, Honfleur, all part of the Le Havre command.
15th: Combined Fleet sighted off Falmouth (45 SOL).
16th:  Fleet spotted at dawn off Plymouth.
By this date the French suffering from rampant sickness, But D’Orvilliers still hoped to be able to master the Channel, and cover an invading army. 
17th:  Enemy fleet stands in towards Plymouth Sound, but not yet in range. Hardy (now with 38 SOL) first hears of the Combined Fleet’s presence in the Channel. In Portsmouth a boom was laid across the harbour.
18th: Combined Fleet spotted six leagues from the Sound.  French hear that D’Orvilliers having difficulty entering the channel due to unfavourable winds.
19th: Combined Fleet had vanished from sight.
22nd: Combined Fleet 22 leagues off N-W of Ushant.
23rd News received in France that D’Orvilliers was in the Channel.
25th: Combined Fleet pursues Hardy, having spotted him SW of the Scillies.
26th: The start of several days of foggy weather.  French troops were put on 24 hours alert to embark.  Harcourt mentions the Regiments La Couronne, Lisieux, 2 battalions of Pont-l’Eveque and 2 battalions du Roi under his commands, and that he had replaced 6 squadrons of artillery (70 horse artillery who had left for St-Malo) that had not yet arrived by 50 hussars de Chamboran. Rumours were that D’Orvilliers was at St Helens, but Harcourt believed this incorrect. Harcourt had embarked all the campaign effects and equipment of the regiments. Troops being ordered to be moved to embarkation points.
27th: Change in wind enables D’Orvilliers to head for the Scillies.
By 28th: French all ready for embarkation having put provisions aboard. Soissonais Reg’t mentioned with Harcourt. Chatelet writes an interesting letter to Harcourt detailing concerns, plans and possibilities, adding that all will be ready for an invasion within 48 hours.  Reg’ts Beauce, Sosissonais and 6 companies de Toul (artillery) embarked at Le Havre.
29th: Fleets sight each other when the fog lifts for a few hours in the afternoon and Hardy forms his in line. Cannon fire heard all day by a neutral ship.
30th: Light winds, and fog comes down again. Cannon fire again heard all day by a neutral ship.
31st: Only four cannon shots reported by the neutral ship. Hardy had succeeded in getting ‘inside’ the enemy, and was aiming to draw them up the Channel into increasingly unfamiliar waters. Combined Fleet being out sailed and struggling badly.
1st: Hardy anchors off Plymouth.
2nd: Hardy weighs anchor to head for Spithead (arrives on 3rd) and seen entering via the Needles from the 2nd to 3rd.
 8th Harcourt expresses dismay that the campaign may not now go ahead.
10th to 15th September: Combined Fleet struggles into Brest.



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