São João del-Rei is a Brazilian municipality in the state of Minas Gerais. Founded in 1713 in homage to king John V of Portugal, the city is fa…São João del-Rei is a Brazilian municipality in the state of Minas Gerais. Founded in 1713 in homage to king John V of Portugal, the city is famed for its historic Portuguese colonial architecture. The current population is estimated at 90,225 inhabitants.