Dom Pedro I was the founder and first ruler of the Empire of Brazil, where he was known as "the Liberator". As King Dom Pedro IV, he reigned briefly over Portugal, where he also became known as "the Liberator" as well as "the Soldier King". Born in Lisbon, Pedro I was the fourth child of King Dom John VI of Portugal and Queen Carlota Joaquina, and thus a member of the House of Braganza. When the country was invaded by French troops in 1807, he and his family fled to Portugal's largest and wealthiest colony, Brazil.

The Empire of Brazil was a 19th-century state that broadly comprised the territories which form modern Brazil and Uruguay until the latter achieved independence in 1828. Its government was a representative parliamentary constitutional monarchy under the rule of Emperors Pedro I and his son Pedro II. A colony of the Kingdom of Portugal, Brazil became the seat of the Portuguese Empire in 1808, when the Portuguese Prince regent, later King Dom John VI, fled from Napoleon's invasion of Portugal and established himself and his government in the Brazilian city of Rio de Janeiro. John VI later returned to Portugal, leaving his eldest son and heir-apparent, Pedro, to rule the Kingdom of Brazil as regent. On 7 September 1822, Pedro declared the independence of Brazil and, after waging a successful war against his father's kingdom, was acclaimed on 12 October as Pedro I, the first Emperor of Brazil. The new country was huge, sparsely populated, and ethnically diverse.