Lamy became Deputy Secretary General, then Secretary General of the Interministerial Committee for the Remodelling of Industrial Structures (CIASI) in the Treasury Department. When Delors became President of the European Commission in 1984, he took Lamy with him to serve as chef de cabinet, which he did until the end of Delors' term in 1994. During his time there, Lamy became known as the "Beast of the Berlaymont", the "Gendarme" and "Exocet" due to his habit of ordering civil servants, even Directors-General (heads of department) "precisely what to do – or else." He was seen as ruling Delors' office with a "rod of iron", with no-one able to bypass or manipulate him and those who tried being "banished to one of the less pleasant European postings".