Senegal was a series of important trading posts on the West Coast of Africa and the river of the same name; it was particularly important in the slave trade. England briefly occupied Senegal from the French in 1693. The other navigable river of note nearby was the Gambia which England would hold on to for most of this era.
The British would move into Senegal with more force in 1758 as a result of the world wide fighting of the Seven Years War. That war was generally successful for the British and so she held on to the colony at the end of it. In fact, it would be combined with the Gambian colony to make the colony known as Senegambia. However, this colony was to last barely two decades. In the American Revolutionary Wars the French took the opportunity to retake Senegal and also the Gambia this time. At the conclusion of the war in 1783, Senegal was returned to the French, whilst Gambia was restored to the British.
During the Napoleonic Wars, French Privateers had been found to be using this French colony as a base to restock and re-arm before continuing their actions against the Royal Navy and British shipping in the area. Hence the Royal Navy decided to seize the colony once more. On 4th July 1809, a small British fleet set sail from the British colony of Sierra Leone. The Solebay, Derwent, Tigress, George and the troopship Agincourt carrying 166 soldiers from the Royal African Corps arrived off the Senegal River on the evening of the 7th July. They anchored off the Senegal bar not far from the colony's capital St. Louis. This bar was a formidable barrier to large ships with just a single opening for large ocean going ships but with no maps available to the British mariners. Therefore, over 300 soldiers, marines and sailors were disembarked and sent towards the shoreline as the Royal Naval ships use lead weights to try to discover the channel for entry. Unfortunately a large wave hit one of the boats heading ashore and capsized it. Captain Parker and 7 other men were drowned. The rest of the troops got ashore but HMS George ran aground shortly after this event. Fortunately it became clear that the French garrison had already vacated the St. Louis settlement when they first saw the British ships arrive and had fallen back to the next sandbar and boom 10 miles upstream to the fort at Babague. The British marched over land as HMS George was refloated on 10th July. A french sally out of Babague was quicky seen off by the British troops and the French retreated once more to their fort and defences. This was quite an intimidating line of defences awaiting the British. In addition to the fort, there was a battery on the south point of an island commanding the only passage to the river. There was a further battery a quarter of mile downriver of this covering the chain boom. Behind this boom were 7 armed vessels mounting a total of 31 guns between them. HMS Solebay and HMS Derwent opened fire on the French vessels at range and did considerable damage over the course of July 11th. Unfortunately that night and in the cramped conditions of the riverway HMS Solebay ran aground after a heavy swell almost made her run into HMS Derwent. Nobody was killed, but the ship was wrecked. Despite this setback, the British prepared for an all out assault on the defences. All the soldiers and marines were reembarked on the 12th and the flotilla proceeded up river until within range of the fort at Babague. They were waiting to launch a night attack when they received a message that the French wish to discuss surrender terms. The attack was therefore postponed for that night. In the morning, the British discovered that the boom had been damaged, the armed vessels and shore batteries had been abandoned. It appears that nerve of the French militia had collapsed and that they had damaged the boom themselves to avoid the need for a fight.
On 13th July, the French commandant of Senegal formally surrendered the colony to the British. The 400 odd French Prisoners of War were eventually repatriated to France under parole terms. Senegal was to be administered largely from Sierra Leone and via the Royal Navy. It would remain under British control until 1816 when it was finally handed back to the French as part of the Congress of Vienna terms upon the end of the Napoleonic Wars.