The first independent German Animal Welfare Act ("Reichstierschutzgesetz") was enacted in 1933. It was not until 1972 that it was superseded by the German Animal Welfare Act (TierSchG), which took over essential provisions from the Nazi legislation. The core principle of the Animal Welfare Act is: "No one may cause an animal pain, suffering or harm without good reason" (§ 1). The most recent extensive amendment of the Animal Welfare Act came into force on 13 July 2013. With regard to animal experiments, most of the changes made in this amendment were prompted by Directive 2010/63/EU issued by the European Parliament in 2010. Among others, regulations for experiments on monkeys were tightened; the use of great apes as laboratory animals is now forbidden, save for a few exceptions.