The British seizure of Saint Lucia in 1778 gave them a position from which to watch the main French base at Martinique, and a stronger British fleet defeated d'Estaing's relief attempt. Both navies then received and lost ships as convoys and wider theatres demanded them, leaving each side uncertain about the other's strength. D'Estaing first aimed at Jamaica, but adverse winds pushed him toward St Vincent, which fell on 18 June 1779. He tried for Jamaica again, then captured Grenada on 4 July. When the British returned from convoy duty, intelligence that the French were at Grenada set the two fleets on course for battle.
Chapter · 45:36-51:32
Saint Lucia, St Vincent, and Grenada reshape the campaign
British control of Saint Lucia, shifting reinforcements, and French captures at St Vincent and Grenada set the conditions for the fleet battle.