Why did Rio de Janeiro become Brazil's colonial capital in 1763?

The Portuguese government transferred the colonial capital of Brazil from Salvador to Rio de Janeiro in 1763 primarily due to the economic shift caused by the discovery of gold and diamonds in the nearby region of Minas Gerais during the early 18th century.123

The mining boom brought vast wealth into the Southeast, fundamentally altering the colony's economic landscape and necessitating a more centralized administrative presence near the source of this new prosperity. As Rio de Janeiro became the primary trade center for these mining areas, its economic and social prominence grew, leading the Portuguese crown to relocate the capital to better manage the region's burgeoning wealth and institutional needs.234