 The Raid on Saint @-@ Paul was an amphibious operation conducted by a combined British Army , Royal Navy and Royal Marines force against the fortified French port of Saint Paul on Île Bonaparte ( now known as Réunion ) during the Napoleonic Wars . The operation was launched on 20 September 1809 as both a precursor to a future full @-@ scale invasion of Île Bonaparte and in order to capture the French frigate Caroline and the East Indiamen she had seized in the Action of 31 May 1809 which were sheltering in the harbour . The operation was a complete success , with British storming parties capturing the batteries overlooking the port , which allowed a naval squadron under Commodore Josias Rowley to enter the bay and capture the shipping in the harbour . 
