de Oliveira was one of the Conversos surnames adopted by Sephardic families after converting (often forced) to Christianity.
The de Oliveira and their cousins Benveniste and Antunes arrived largely and concentrated mainly in the Northeast Region and Minas Gerais in southeast Brazil.
Rabbi Abraham Benveniste who was born in 1433, in Soria, Cáceres, adopted the De Oliveira family name in Portugal.
He was a direct descendant of Rabbi Zerahiá ben-Its'haq ha-Levi and Gerona, who lived in the 12th century and was called ha-Its'hari, or Its'hari, because his genealogy goes to the children of Its'har, who was uncle of the prophet Moshe Rabenu.
The offspring of the tribe of Levy and Hebron intentionally settled between Spain, Galicia and Portugal for two reasons, first because it is inland and far from the great centers of Spain, where the first killings of Judeans or pogroms began, promoted by Catholic priests of the Dominican and Carmelite orders, which urged the old Christian population to kill the New Christian former-Jews and the unconverted Judeans and also gave them freedom to cross the borders among the different countries accordingly to the laws of each State.