first film that the foundation chose to sponsor was Oliveira's next feature, and the early 1970s would come to be known as the Gulbenkian Years of Portuguese cinema. 1970–89: Artistic breakthrough: Tetralogy of Frustrated Love and recognition From the 1970s, Oliveira was at his most active, with the vast majority of his films having been made after he turned 75. Whether a late bloomer or a victim of unfortunate delays and political censorship, he became Portugal's preeminent filmmaker during the later part of his long life. Film critic J. Hoberman has said "at an age when many men think of retirement, Oliveira emerged from obscurity as one of the 70s leading modernists, a peer of Straub, Syberberg and Duras." With a newfound artistic freedom after António de Oliveira Salazar's stroke in 1968 and the April 1974 Carnation Revolution, Oliveira's career began to flourish and receive international acclaim. Ironically the Carnation Revolution also resulted in his family's factories being occupied by factions of the Left and subsequently going bankrupt. Due to this, Oliveira lost most of his personal wealth and his home of thirty-five years. Oliveira's second return to filmmaking came in 1971 with Past and Present (O Passado e o Presente), a satirical black comedy on marriage and the bourgeoisie. With its lyrical surrealism and farcical situations, the film was a shift from his earlier work about lower-class people. Based on a play by Vicente Sanches, the film stars Maria de Saisset as Vanda, a woman who only falls in love with her husbands after they have died. Past and Present was the first of what has become known as Oliveira's "Tetralogy of frustrated loves". It was followed by Benilde or the Virgin Mother, Doomed Love and Francisca. Each of these films share the theme of unfulfilled love, the backdrop of a repressive society, and the beginning of Oliveira's unique cinematic style. Benilde or the Virgin Mother (Benilde ou a Virgem Mãe) was based on a play by Oliveira's long-time friend and fellow Salazar regime dissident José Régio and released in 1975. This would be the first of many films that would examine the relationship between film and theater in Oliveira's work, and the film opens with roaming exterior shots of the Tobis Studios in Lisbon until reaching the constructed set of the film. In the film Benilde is a sleepwalking eighteen-year-old who mysteriously becomes impregnated and believes herself to