A small, glittering jewel in the Indian Ocean, and a favorite destination of honeymooners, Mauritius is as near as you get to a real island paradise. Though there have been some dire predictions about the threat of rising sea levels due to global warming, today the island is relatively untroubled by geopolitical currents. But during the Napoleonic era, this tiny speck, isolated in the vastness of the sea and surrounded by coral reefs, was a prized asset in the imperial contest between Britain and France.

Held by Napoleon and coveted by the English, Ile-de-France (as it was then known) provided France a base to harass British shipping. French frigates, along with privateers out for booty, sallied forth, preying on British ships laden with vital commodities from India. The British considered the island so important that William Pitt, the British prime minister, declared, “As long as the French hold Ile-de-France, the British will never be masters of India.” The British had dithered in their attempts to wrest it from the French, a strategic miscalculation that baffled Napoleon — “It’s sheer idiocy on their part,” he said — but gave his ships the upper hand. The British navy might have ruled the waves, but not in this part of the world.

As Stephen Taylor writes in “Storm and Conquest” (W.W. Norton, 380 pages, $26.95), his unwieldy account of the battles in and around Ile-de-France, “The benefits of Trafalgar had not been felt in the Eastern seas … Here alone the French retained a capacity to strike at Britain’s commercial lifeline.” A multipart story of war and really bad weather, Taylor’s book focuses on a dreadful two-year period (1808–1810) when a series of calamities severely battered the royal navy and the British East India Company’s fleet of Indiamen, which were carrying supplies of Bengali saltpeter (a key ingredient in gunpowder) for the British army. French frigates captured several vessels, and two freak hurricanes sent many more to the bottom, along with tons of saltpeter. All told, some 1,000 lives were lost in these disasters.

One has a sense that Mr. Taylor isn’t quite sure what kind of story he wanted to write; the storm and the conquest seem like separate books altogether. The geographic reach of his story is vast. He ranges from Madras to the Cape of Good Hope, where the British had an important base, to London and life at sea as he weaves together a host of subsidiary dramas — scandalous affairs, shipboard mutinies, and near revolt of British officers in India. There are dozens of characters to keep track of, including Robert Corbet, an infamous royal navy captain of Bligh-like ferocity — he was quick to use the lash — and General Charles Decaen, the crafty governor of Ile-de-France. The effect of all this puts a strain on Mr. Taylor’s narrative, which chugs along in fits and starts. Mr. Taylor also has a weakness for cliché (“Caledon was not to be fobbed off”) and purple prose straight out of the “It was a dark and stormy night” handbook (“That left only the Nereide — the tragic, doomed Nereide”).

Still, there is much terror and excitement on Mr. Taylor’s pages. Using logs from the surviving ships, he carefully reconstructs the events of the storms, and judiciously speculates what happened to the ships that were lost in the monster seas. (Captains who survived the twin storms referred to each as “a perfect hurricane.”) Even experienced sailors were put to the test by the storms, which wreaked havoc on the vessels. But, as Mr. Taylor explains, a decisive factor in the calamities that befell the fleets was entirely man-made: The royal navy had pressed hundreds of sailors from the Indiamen into military service, leaving the commercial vessels disastrously undermanned.

In his second section, he details the bloody fight for Ile-de-France, which the English took at great cost. The French warships were lean, fast, heavily armed, and matched up well against the greatest naval power in the world. Though British troops captured the nearby island of Bourbon (now Reunion), Ile-de-France proved a greater obstacle. In August of 1810, during the Battle of Grand Port, the French took two British Indiamen, and put several other warships out of service, dealing the royal navy a shocking blow. The battle did not change history but, as Mr. Taylor notes, “symbolically, it was hugely significant — the only French naval victory of the Napoleonic wars, which made it not so much a defeat as a violation of the natural order.”

Between storm and battle, British sailing power was nearly overwhelmed. But the French had little time to enjoy their triumph. A new squadron of royal navy ships, including one captained by Corbet, descended on Ile-de-France a month later to restore the natural maritime order. The engagement began badly for the British, who lost several ships, but the French did not move in for the kill. With a giant armada of British troopships bearing down on the island, the game was up. The French surrendered, and Britain’s passage to India was secured. As the triumphant British admiral crowed in his report to the admiralty, “I have the honor to announce the capture of the Isle of France and its dependencies, comprehending the extirpation of the Naval Force of the Enemy in these seas and the subjugation of the last remaining colonial territory of France.”

Mr. Price is a contributor to Bookforum and other publications.