Why did Salvador lose political importance after 1763?

Salvador lost its political preeminence in 1763 primarily because the colonial seat of government was transferred from the city to Rio de Janeiro.12

This administrative shift occurred as the focus of the colonial economy moved toward the south-central region. Following the discovery of major gold and diamond deposits in Minas Gerais during the 18th century, Rio de Janeiro emerged as a vital urban and institutional center to manage the colony's new mineral wealth. While the northeastern sugar industry remained economically significant, the gold region offered newer wealth and higher profitability, causing distant regions to orient their activities toward the south.23

Following the loss of its status as the capital, Salvador entered a long period of economic decline that lasted until after 1900.1