Napoleon's invasion plan and its sea-control problem

The scheme began with the Brest and Toulon forces breaking separate British blockades. Villeneuve's Toulon fleet was then supposed to gather Spanish ships from Cartagena and Cadiz before crossing to threaten the West Indies. Napoleon expected that movement to draw William Cornwallis and the main British strength away from the Channel. Nelson and Collingwood's close attention, other British squadrons already overseas, and the difficulty of coordinating two French fleets made that assumption unsafe. The invasion plan could fail during force assembly long before troops approached an English beach.