The captaincy's origin was itself a transaction. In 1709, the Portuguese crown bought the Captaincy of São Vicente from the Marquess of Cascais, merging it into a new administrative unit called the Captaincy of São Paulo and Minas de Ouro -- São Paulo and the Gold Mines. The name revealed the crown's priorities. Gold had been discovered in the interior, and the rush was transforming the region into one of the most valuable territories in the Portuguese empire. But governing a territory that stretched from the Atlantic coast deep into the continental interior proved unwieldy. On December 2, 1720, King John V split the captaincy in two, creating the Captaincy of Minas Gerais as a separate entity. The boundary ran along the Sapucaí and Grande rivers, through the Canastra Mountains to the Paranaíba River. São Paulo kept the coastline. Minas Gerais kept the gold.

What followed was a century and a half of amputation. Between 1738 and 1742, the southernmost reaches became the Captaincy of Santa Catarina and the Military Command of Rio Grande de São Pedro, which would evolve into Rio Grande do Sul by 1807. In 1748, São Paulo lost territory westward when the crown carved out the Captaincy of Goiás and the Captaincy of Mato Grosso. By that point, the captaincy had lost so much autonomy that its own government was effectively suspended. For seventeen years -- from 1748 to 1765 -- São Paulo had no independent governor at all. It took the arrival of Luís António de Sousa Botelho Mourão, the third Majorat of Mateus, to reinstall the captaincy's government and begin founding new towns across its diminished territory.

Even the boundaries that remained were contested. In 1764, the governor of Minas Gerais, Luís Diogo Lobo da Silva, unilaterally annexed the left bank of the Sapucaí River, pushing the border of Minas Gerais roughly to where it stands today. The southern coast around Itanhaém technically belonged to a different captaincy entirely, though in practice São Paulo governed it; the crown finally purchased it from its last holder, the Count of Ilha do Príncipe, in 1753. Even as late as 1820, São Paulo still held the village of Lages in what is now Santa Catarina, until John VI transferred it by royal charter. The last dismemberment came on August 29, 1853, when law 704 elevated the district of Curitiba to the Province of Paraná. After that, São Paulo would never be carved up again -- though its borders with Paraná, Rio de Janeiro, and Minas Gerais were not formally settled until treaties in the 1920s and 1930s.

Governing a territory across such distances and through so many reorganizations generated an enormous volume of paperwork. Starting in 1741, the Secretary of Government of the Captaincy of São Paulo managed the administrative machinery that would function for over eighty years, until 1823. Royal charters, sesmaria land-grant applications, laws, decrees, petitions, and letters accumulated across archives on two continents. Today that paper trail survives in institutions from the Torre do Tombo in Lisbon to the Arquivo Público do Estado de São Paulo, whose collection -- covering everything from slave flight to military campaigns to the construction of churches, roads, and hospitals -- has been certified as Brazilian documentary heritage by UNESCO's Memory of the World Program. On February 28, 1821, the captaincies became provinces; with the proclamation of the republic, the Province of São Paulo became simply São Paulo, the state that now produces roughly a third of Brazil's GDP.