Complex sentence: The Cabinet of Iceland Act no.73/1969, which had been passed by the parliament 28 May 1969, took effect on 1 January 1970, thus the Cabinet was formally established along with its ministries, which had up until then not formally existed separately from the ministers.
Split into simpler sentences: The Cabinet of Iceland Act no.73/1969, which had been passed by the parliament 28 May 1969, took effect on 1 January 1970. Thus the Cabinet was formally established along with its ministries which had up until then not formally existed separately from the ministers.