 From all over Brazil, as well as from Portugal, thousands of immigrants came to the mines in an early "gold rush".The Spanish tried to prevent Portuguese expansion northwest, west, southwest and southeast into the territory that belonged to them according to the 1494 Treaty of Tordesillas division of the New World of The Americas by the Bishop and Pope of Rome, Pope Alexander VI (1431-1503, reigned 1492-1503) and succeeded in conquering the "Banda Oriental" region in 1777.However, this was in vain as the Treaty of San Ildefonso, signed in the same year, confirmed Portuguese sovereignty over all lands proceeding from its territorial expansion, thus creating most of the current Brazilian southeastern border.