The Treason Trial was a trial in Johannesburg in which 156 people, including Nelson Mandela, were arrested in a raid and accused of treason in South Africa in 1956. The main trial lasted until 1961, when all of the defendants were found not guilty. During the trials, Oliver Tambo left the country and was exiled. Whilst in other European and African countries, he started an organisation which helped bring publicity to the African National Congress's cause in South Africa. Some of the defendants were later convicted in the Rivonia Trial in 1964. Chief Luthuli has said of the Treason Trial: