premier of Portugal from September 1968, when he succeeded António de Oliveira Salazar (Salazar, António de Oliveira), until the revolution of April 1974.

Trained as a lawyer, Caetano served with Salazar (then the finance minister) in 1929 and helped to draft the Constitution of 1933 and other legal documents of the New State. Caetano's scholarly writings on civil law and legal and constitutional history, some of them still in print, influenced generations of the educated elite. He was minister of the colonies (1944–47) and deputy prime minister (1955–58), among other posts, before leaving political life to become rector of the University of Lisbon.

When Salazar suffered a stroke in 1968, Caetano was appointed prime minister. He permitted an opposition and rectified the constitution but was unable to curb inflation or appease his critics. Foreign criticism of his economic and energy policies in Portuguese Africa, along with dissatisfaction in the army over the colonial wars in Africa, led to the “Revolution of the Carnations,” which in 1974 overthrew the New State and drove Caetano into exile. He settled in Brazil and served as head of the Institute of Comparative Law, Gama Filho University, Rio de Janeiro, until his death.