The Mafia, a network of organized-crime groups based in Italy and America, evolved over centuries in Sicily, an island ruled until the mid-19th century by a long line of foreign invaders. Sicilians banded together in groups to protect themselves and carry out their own justice. In Sicily, the term “mafioso,” or Mafia member, initially had no criminal connotations and was used to refer to a person who was suspicious of central authority. By the 19th century, some of these groups emerged as private armies, or “mafie,” who extorted protection money from landowners and eventually became the violent criminal organization known today as the Sicilian Mafia. The American Mafia, which rose to power in the 1920s, is a separate entity from the Mafia in Italy, although they share such traditions as omerta, a code of conduct and loyalty.