In 1817, James Hastie, a 30-year-old East India Company sergeant, embarked on an ambitious and risky mission. Under orders from Robert Townsend Farquhar, governor of the new British island colony of Mauritius, seized from the French during the Napoleonic Wars, Hastie undertook a long, perilous overland journey to the highland court of Radama, the young and warlike ruler of the most powerful kingdom in Madagascar. A decade earlier, Britain had banned the slave trade in its colonies and the government in London was pressuring Farquhar to halt the smuggling of slaves to the plantations of Mauritius. Hastie, who had no diplomatic training, lived by his wits as he won Radama's confidence and persuade him to defy the nobles and clan chieftains who profited from the slave trade. From his side, the intelligent, charming yet ruthless Radama skillfully used the British envoy to help win the internal power struggle over political rivals. It was a deal with the devil: in return for banning the slave trade, the British trained Radama's army and supplied muskets and gunpowder, allowing him to expand his dominions, while turning a blind eye to the internal slave trade. As Britain and France continued to face off in the Indian Ocean, competing for trade and power, Hastie secured British influence in Madagascar. He became Radama's most trusted advisor, accompanying him on military campaigns and advocating for social reforms, until his untimely death in 1826.Mission to Madagascar is based on Hastie's unpublished journals, one of them recently discovered, and other primary sources, including letters and political and military dispatches. They offer the most comprehensive early 19th century account of Madagascar, its landscape, crops, industry, commerce, culture, and inhabitants, and weave a narrative of hazardous travel, byzantine court intrigue and colonial geopolitics. This is the first biography of a man whom Sir Mervyn Brown, a former UK ambassador and historian of Madagascar, described as "one of the most important and attractive figures in the history of Anglo-Malagasy relations."