Banditry is the life and practice of bandits. The New English Dictionary on Historical Principles (NED) defined "bandit" in 1885 as "one who is proscribed or outlawed; hence, a lawless desperate marauder, a brigand: usually applied to members of the organized gangs which infest the mountainous districts of Italy, Sicily, Spain, Greece, Iran, and Turkey".
The term bandit (introduced to English via Italian around 1590) originates with the early Germanic legal practice of outlawing criminals, termed *bannan (English ban). The legal term in the Holy Roman Empire was Acht or Reichsacht, translated as "Imperial ban". In modern Italian the equivalent word "bandito" literally means banned or a banned person.
Marauding was one of the most common peasant reactions to oppression and hardship. The growth of warlord armies in China was also accompanied by a dramatic increase in bandit activity in the republican period; by 1930 the total bandit population was estimated to be 20 million.
"Social banditry" is a term invented by the historian Eric Hobsbawm in his 1959 book Primitive Rebels, a study of popular forms of resistance that also incorporate behaviour characterized by law as illegal. He further expanded the field in the 1969 study Bandits. Social banditry is a widespread phenomenon that has occurred in many societies throughout recorded history, and forms of social banditry still exist, as evidenced by piracy and organized crime syndicates. Later social scientists have also discussed the term's applicability to more modern forms of crime, like street gangs and the economy associated with the trade in illegal drugs.