Clifford Walter Dupont, 72, who became president when Rhodesia broke away from Britain in 1965, died Wednesday after a long illness. A former British army officer and a lawyer by profession, Mr. Dupont became the officer administering the government of Prime Minister Ian Smith when it made its Unilateral Declaration of Independence (UDI) from Britain in November 1965.

Set up as a counter figurehead to British Governor Sir Humphrey Gibbs, Mr. Dupont attracted much of the hostility aimed at the illegal regime by anti-UDI elements within Rhodesia and outside the country.

He once described himself as considerably to the right of Mr. Smith in politics, and believed there should be no lowering of white minority standards in Rhodesia.

The London-born Mr. Dupont immigrated to the British colony of Southern Rhodesia in 1948, and bought a tobacco and ranching farm. He entered politics following a double tragedy in 1958, when his first wife died and his children, aged 19 and 11, were killed in an air crash.

In 1962, he became chairman of the Rhodesian Front and helped the party to 16 uninterrupted years of power. In 1964, he defeated former Federal Prime Minister Sir Roy Welensky in a by-election to parliament.

After white Rhodesians had voted for their country to become a republic, Mr. Dupont was sworn in as its first president in April 1970, and remained in the post for more tahn five years.

Mr. Dupont remarried in 1963. He was believed to have spent his retirement handling private investments and tending his farm.