Dom Pedro meant to rule frugally and started by cutting his own salary, centralizing scattered government offices, and selling off most of the royal horses and mules. He issued decrees that eliminated the royal salt tax to spur output of hides and dried beef, forbade arbitrary seizure of private property, required a judge's warrant for arrests of freemen, and banned secret trials, torture, and other indignities. He also sent elected deputies to the Côrtes in Portugal. However, slaves continued to be bought and sold and disciplined with force, despite his assertion that their blood was the same color as his. In September 1821, the Côrtes, with only a portion of the Brazilian delegates present, voted to abolish the Kingdom of Brazil and the royal agencies in Rio de Janeiro and to make all the provinces subordinate directly to Lisbon. Portugal sent troops to Brazil and placed all Brazilian units under Portuguese command. In January 1822, tension between Portuguese troops and the Luso-Brazilians (Brazilians born in Portugal) turned violent when Pedro accepted petitions from Brazilian towns begging him to refuse the Côrtes's order to return to Lisbon. Responding to their pressure and to the argument that his departure and the dismantling of the central government would trigger separatist movements, he vowed to stay. The Portuguese "lead feet," as the Brazilians called the troops, rioted before concentrating their forces on Cerro Castello, which was soon surrounded by thousands of armed Brazilians. Dom Pedro "dismissed" the Portuguese commanding general and ordered him to remove his soldiers across the bay to Niteroi, where they awaited transport to Portugal. Pedro formed a new government headed by José Bonifácio de Andrada e Silva of São Paulo. This former royal official and professor of science at Coimbra was crucial to the subsequent direction of events and is regarded as one of the formative figures of Brazilian nationalism, indeed, as the patriarch of independence.

The atmosphere was so charged that Dom Pedro sought assurances of asylum on a British ship in case he lost the looming confrontation; he also sent his family to safety out of the city. In the following days, the Portuguese commander delayed embarcation, hoping that expected reinforcements would arrive. However, the reinforcements that arrived off Rio de Janeiro on March 5, 1822, were not allowed to land. Instead, they were given supplies for the voyage back to Portugal. This round had been won without bloodshed.

Blood had been shed in Recife in the Province of Pernambuco, when the Portuguese garrison there had been forced to depart in November 1821. In mid-February 1822, Bahians revolted against the Portuguese forces there but were driven into the countryside, where they began guerrilla operations, signaling that the struggle in the north would not be without loss of life and property. To secure Minas Gerais and São Paulo, where there were no Portuguese troops but where there were doubts about independence, Dom Pedro engaged in some royal populism.

Towns in Minas Gerais had expressed their loyalty at the time of Pedro's vow to remain, save for the junta in Ouro Prêto, the provincial capital. Pedro realized that unless Minas Gerais were solidly with him, he would be unable to broaden his authority to other provinces. With only a few companions and no ceremony or pomp, Pedro plunged into Minas Gerais on horseback in late March 1822, receiving enthusiastic welcomes and allegiances everywhere. Back in Rio de Janeiro on May 13, he proclaimed himself the "perpetual defender of Brazil" and shortly thereafter called a Constituent Assembly (Assembléia Constituinte) for the next year. To deepen his base of support, he joined the freemasons, who, led by José Bonifácio Andrada e Silva, were pressing for parliamentary government and independence. More confident, in early August he called on the Brazilian deputies in Lisbon to return, decreed that Portuguese forces in Brazil should be treated as enemies, and issued a manifesto to "friendly nations." The manifeso read like a declaration of independence.

Seeking to duplicate his triumph in Minas Gerais, Pedro rode to São Paulo in August to assure himself of support there and began a disastrous affair with Domitila de Castro that would later weaken his government. Returning from an excursion to Santos, Pedro received messages from his wife and from Andrada e Silva that the Côrtes considered his government traitorous and was dispatching more troops. In a famous scene at Ipiranga on September 7, 1822, he had to choose between returning to Portugal in disgrace or opting for independence. He tore the Portuguese blue and white insignia from his uniform, drew his sword, and swore: "By my blood, by my honor, and by God: I will make Brazil free." Their motto, he said, would be "Independence or Death!"

Pedro's government employed Admiral Thomas Alexander Cochrane, one of Britain's most successful naval commanders in the Napoleonic Wars and recently commander of the Chilean naval forces against Spain. Pedro's government also hired a number of Admiral Cochrane's officers and French General Pierre Labatut, who had fought in Colombia. These men were to lead the fight to drive the Portuguese out of Bahia, Maranhão, and Pará, and to force those areas to replace Lisbon's rule with that of Rio de Janeiro. Money from customs at Rio de Janeiro's port and local donations outfitted the army and the nine-vessel fleet. The use of foreign mercenaries brought needed military skills. The much-feared Cochrane secured Maranhão with a single warship, despite the Portuguese military's attempt to disrupt the economy and society with a scorched-earth campaign and with promises of freedom for the slaves. By mid-1823 the contending forces numbered between 10,000 and 20,000 Portuguese, some of whom were veterans of the Napoleonic Wars, versus 12,000 to 14,000 Brazilians, mostly in militia units from the Northeast.

Some historians have erred in supporting historian Manuel de Oliveira Lima's contention that independence came without bloodshed. In fact, although both sides avoided massive set battles, they did engage in guerrilla tactics, demonstrations, and countermoves. There is little information on casualties, but the fighting provided a female martyr in Mother Joana Angélica, who was bayoneted to death by Portuguese troops invading her convent in Bahia; and an example of female grit in Maria Quitéria de Jesus, who, masquerading as a man, joined the imperial army and achieved distinction in several battles.

Britain and Portugal recognized Brazilian independence by signing a treaty on August 29, 1825. Until then, the Brazilians feared that Portugal would resume its attack. Portuguese retribution, however, came in a financial form. Secret codicils of the treaty with Portugal required that Brazil assume payment of 1.4 million pounds sterling owed to Britain and indemnify Dom João VI and other Portuguese for losses totaling 600,000 pounds sterling. Brazil also renounced future annexation of Portuguese African colonies, and in a side treaty with Britain promised to end the slave trade. Neither of these measures pleased the slave-holding planters.

Organizing the new government quickly brought the differences between the emperor and his leading subjects to the fore. In 1824 Pedro closed the Constituent Assembly that he had convened because he believed that body was endangering liberty. As assembly members, his advisers, José Bonifácio de Andrada e Silva and Dom Pedro's brothers, had written a draft constitution that would have limited the monarch by making him equal to the legislature and judiciary, similar to the president of the United States. They wanted the emperor to push the draft through without discussion, which Pedro refused to do. Troops surrounded the assembly as he ordered it dissolved. He then produced a constitution modeled on that of Portugal (1822) and France (1814). It specified indirect elections and created the usual three branches of government but also added a fourth, the moderating power, to be held by the emperor. The moderating power would give the emperor authority to name senators and judges and to break deadlocks by summoning and dismissing parliaments and cabinets. He also had treaty-making and treaty-ratifying power. Pedro's constitution was more liberal than the assembly's in its religious toleration and definition of individual and property rights, but less so in its concentration of power in the emperor.

The constitution was more acceptable in the flourishing, coffee-driven Southeastern provinces than in the Northeastern sugar and cotton areas, where low export prices and the high cost of imported slaves were blamed on the coffee-oriented government. In mid-1824, with Pernambuco and Ceará leading, five Northeastern provinces declared independence as the Confederation of the Equator, but by year's end the short-lived separation had been crushed by Admiral Cochrane. With the Northeast pacified, violence now imperiled the South.

In 1825 war flared again over the Cisplatine Province, this time with Buenos Aires determined to annex the East Bank. The empire could little afford the troops, some of whom were recruited in Ireland and Germany, or the sixty warships needed to blockade the Río de la Plata. A loan from London bankers was expended by 1826, and Pedro had to call the General Assembly to finance the war. The blockade raised objections from the United States and Britain, and reverses on land in 1827 made it necessary to negotiate an end to the US$30 million Cisplatine War. The war at least left Uruguay independent instead of an Argentine province. In June 1828, harsh discipline and xenophobia provoked a mutiny of mercenary troops in Rio de Janeiro; the Irish were shipped home and the Germans sent to the South. The army was reduced to 15,000 members, and the antislavery Pedro, now without military muscle, faced a Parliament controlled by slaveowners and their allies.

As coffee exports rose steadily, so did the numbers of imported slaves; in Rio de Janeiro alone they soared from 26,254 in 1825 to 43,555 in 1828. In 1822 about 30 percent, or 1 million, of Brazil's population were African-born or -descended slaves. Slavery was so pervasive that beggars had slaves, and naval volunteers took theirs aboard ship.

Pedro had written that slavery was a "cancer that is gnawing away at Brazil" and that no one had the right to enslave another. He wanted to abolish slavery, but his own liberal constitution gave the law-making authority to the slavocrat-controlled Parliament. In Brazil liberal principles and political formulas were given special meaning. The language of social contract, popular sovereignty, supremacy of law, universal rights, division of powers, and representative government was stripped of its revolutionary content and applied only to a select, privileged minority.

After 1826 the slavocrat agenda was to control the court system; to provide harsh punishments for slave rebellion but mild ones for white revolt; to reduce the armed forces, cleansing them of foreigners unsympathetic to slavery; to keep tariffs low and eliminate the Bank of Brazil in order to deny the central government the ability to stimulate a rival, finance-based industrial capitalism; and to shape immigration policy in such a way as to encourage servile labor instead of independent farmers or craftsmen. Led by Bernardo Pereira de Vasconcelos of Minas Gerais in the assembly, slavocrats argued that slavery was not demoralizing, that foreign capital and technology would not help Brazil, and that railroads would only rust. Others, such as Nicolau de Campos Vergueiro of São Paulo, argued in favor of replacing slavery with free European immigrants. In the end, the Parliament established a contract system that was little better than slavery. There would be no liberal empire. Laws and decrees unacceptable to the slavocrats simply would not take effect, such as the order in 1829 forbidding slave ships to sail for Africa. These items of the slavocrat agenda were the roots of the regional rebellions of the nineteenth century.

After Dom João's death in 1826, despite Pedro's renunciation of his right to the Portuguese throne in favor of his daughter, Brazilian nativist radicals falsely accused the emperor of plotting to overthrow the constitution and to proclaim himself the ruler of a reunited Brazil and Portugal. They raised tensions by provoking street violence against the Portuguese of Rio de Janeiro and agitated for a federalist monarchy that would give the provinces self-government and administrative autonomy. Brazil's fate was in the hands of a few people concentrated in the capital who spread false stories and undermined discipline in the army and police. It would not be the last time that events in Rio de Janeiro would shape the future. When Pedro dismissed his cabinet in April 1831, street and military demonstrators demanded its reinstatement in violation of his constitutional prerogatives. He refused, saying: "I will do anything for the people but nothing [forced] by the people." With military units assembled on the Campo Santana, an assembly ground in Rio de Janeiro, and people in the streets shouting "death to the tyrant," he backed down. Failing to form a new cabinet, he abdicated in favor of his five-year-old son Pedro II, boarded a British warship, and left Brazil as he had arrived, under the Union Jack.

Data as of April 1997