Mikis Theodorakis, the celebrated Greek composer of “Zorba the Greek,” “Z” and “Serpico” and among the most politically active of all 20th-century composers, died Thursday at his home in Athens. He was 96.

His official website listed the cause of death as cardiopulmonary arrest. “Today we lost a part of Greece’s soul,” Greece’s cultural minister, Lina Mendoni, said on Twitter. “Mikis Theodorakis, Mikis the teacher, the intellectual, the radical, our Mikis, has gone.”

Greek president Katerina Sakellaropoulou called him a “pan-Hellenic personality… a universal artist, an invaluable asset of our musical culture,” and Prime Minister Kyriakos Mitsotakis announced three days of national mourning.

Theodorakis’ colorful score for the 1964 “Zorba the Greek,” starring Anthony Quinn and Alan Bates, was an international hit (its soundtrack album reached the top 30 of Billboard’s album charts) with its infectious “Zorba’s Dance” and its unusual bouzouki sounds. It was nominated for a Grammy and a Golden Globe. The dance became known as sirtaki and “Zorba’s Dance” was covered numerous times, including by Herb Alpert and the Tijuana Brass.

As director Michael Cacoyannis said at the time, “Theodorakis succeeded in creating music of such inner excitement and stirring rhythms as to match the glorious defiance of Zorba’s spirit.” They did five other films together, including adaptations of classic literature (“Electra” in 1962, “The Trojan Women” in 1971, “Iphigenia” in 1977), a contemporary comedy (“The Day the Fish Came Out,” 1977) and a Biblical story for television (“The Story of Jacob and Joseph,” 1974).

Theodorakis’ political activities inspired later film-music masterpieces. He was elected three times to the Greek Parliament, first as a left-wing deputy in 1964, and his outspoken nature resulted in his music being banned by the military junta that took power in 1967. He was jailed, then interned in a concentration camp, and – after international pressure by fellow artists including Leonard Bernstein, Arthur Miller and Harry Belafonte – exiled in 1970.

The Greek-French film director Costa-Gavras insisted on his music for “Z,” the 1969 political thriller loosely based on the 1963 assassination of Greek anti-war activist Grigoris Lambrakis. Theodorakis wrote a compelling score in secret, the music smuggled out and recorded in Paris; it won the BAFTA as the year’s best score in 1970.

Costa-Gavras reunited with Theodorakis for another political thriller, 1972’s “State of Siege,” about terrorist kidnappings in South America; the composer’s use of traditional Latin American folk instruments resulted in one of his most evocative scores. And in 1973, Theodorakis wrote the music for Sidney Lumet’s “Serpico,” about corruption in the New York City police department. Both scores were BAFTA nominated; “Serpico,” with arrangements by American jazz artist Bob James, also earned a Grammy nomination.

After the overthrow of the Greek military regime, Theodorakis returned to Greece in 1974, continuing both his musical career and his political activities. He was re-elected to the Greek Parliament in 1981 (as a Communist) and 1989 (as a Democrat), and in the 1990s he became general music director of Hellenic Radio and Television orchestras. And while he continued to score the occasional European film, most of his music was in the classical realm including several symphonies, operas and song cycles.

He was born in Chios, a Greek island in the Aegean Sea, in 1925. He studied music at the Athens Conservatory during the 1940s and later on a state scholarship in Paris during the early 1950s. His early works, including a piano concerto, a symphony, and four ballets, written during the late 1950s, received international acclaim (including a gold medal at the 1957 Moscow Music Festival).

Theodorakis’ other scores for notable directors included “Ill Met by Moonlight,” for British filmmakers Michael Powell and Emeric Pressburger in 1957; “Phaedra” for Jules Dassin in 1962; and “Five Miles to Midnight” for Anatole Litvak in 1962.

Survivors include his wife Myrto Altinoglou, daughter Margarita Theodoraki and son George Theodorakis.