In March 1933 a regional SA regiment established a concentration camp in a disused factory building in the centre of Oranienburg. In the three months after the National Socialists seized power, Oranienburg concentration camp took on a key role in the persecution of the opposition in Berlin – the capital city of the 'Reich'. Around 3000 people were held in the camp until its closure in 1934 and at least 16 prisoners were murdered by the guards.