Dias led a military regiment composed of enslaved and free Afro-Brazilians and was known as "Governor of the Blacks" in 1636. Dias defended Portuguese settlements from Dutch forces and played important roles in the First and Second Battles of Guararapes, in the defense of Salvador, Bahia, and to restore Portuguese control over Pernambuco. Dias' title was expanded to "Governor of All Creoles, Blacks, and Mulattoes," in 1639.