On the twelfth of October 1798, a prince was born in a pink baroque palace outside Lisbon. Thirty-five years later, he died in that same palace - and in between, he had declared a country independent, crowned himself emperor, drafted a constitution, fought a siege lasting thirteen months, restored a stolen throne to his daughter, and left his heart to a city in northern Portugal. No single national narrative can contain him. He was the Liberator of Brazil and the Soldier King of Portugal, and he was the same man.

Barrett McMahon's The Transatlantic Liberator is the first full-length narrative biography to hold both careers in a single frame. Drawing on the Brazilian independence crisis of 1822, the constitutional battles of the 1820s, the Liberal Wars of 1832-1834, and the intimate human drama of two marriages, a great scandal, and a political collapse, McMahon reconstructs one of the most extraordinary lives of the Atlantic age. This is the story of a man made by the Napoleonic transformation of the old world and remade by the colonial energy of the new - who governed imperfectly, fought courageously, failed publicly, and built institutions that outlasted his career by generations. Urgent, rigorous, and deeply human, The Transatlantic Liberator argues that to understand the remaking of the modern Atlantic world, you must start here.