The accord reached yesterday between Prime Minister Ian Smith and black leaders came more than 12 years after Smith first challenged world opinion by declaring Rhodesian independence. Here is achronology of those years of political, economic and military pressure from Rhodesian nationalists and from African and Western nations:

Nov. 11, 1965: Smith and his wife constituency unilaterally declare independence from Britain to stave off the transfer of power to a black government. Britain terms the act illegal and slaps economic sanctions on the "rebel" state. Local press censorship is imposed.

Nov. 20, 1965: The U. N. Security Council calls on all nations to stop oil shipments to Rhodesia, the first of several economic sanctions imposed on Rhodesia by the world body.

Dec. 2-3, 1966: Prime Ministers Smith of Rhodesia and Harold Wilson of Britain meet on the British warship Tiger in the Mediterranean in an effort to resolve the dispute. Rhodesian Cabinet rejects British proposals.

Oct. 9-13, 1968: Second round of talks begins with Smith and Wilson abroad warship Fearless at Gilbraltar. They fail.

March 2, 1970: Rhodesia declares itself a republic.

Nov. 24, 1971:

Independence agreement signed in Salisbury between Smith and British Prime Minister Sir Alec Douglas-Home, subject to acceptability by Rhodesian blacks.

March 24, 1972: Pearce Commission of Britain, after testing public opinion, reports independence terms reached by Douglas-Home and Smith not acceptable to blacks.

Dec. 22, 1972: White homestead at Centenary attacked by black nationalist guerillas, marking onset of insurgency in which an estimated 8,000 person have died in fighting within Rhodesia and in neighboring nations.

Jan. 9, 1973: Smith closes border with Zambia, which harbors guerrillas fighting in Rhodesia. The move blocks major trading route for landlocked Zambia.

April 25, 1974: Coup in Portugal which leads to independence of the Portuguese colonies in Africa - Mozambique and Angola. This, in turn, causes South Africa to pull back on its policy of strong support for Rhodesia.

Dec. 11, 1974: Smith announces release of detained black nationalist leaders, including Joshua Nkomo and the Rev. Ndabaningi and constitutional talks in 1975.

July 1, 1975: South Africa announces withdrawal of 2,000 special police who were backing Rhodesian forces against guerrillas.

Aug. 25, 1975: Smith meets with black leaders of African National Council on Victoria Falls Bridge spanning Zambesi River for constitutional talks, which collapse the next day. Smith says he will seek settlement with moderate blacks inside the country.

March 3, 1976: Mozambique closes border with Rhodesia and declares that a state of war exists. Later, Smith orders first of scores of raids on guerrilla camps in Mozambique.

April 27, 1976: U. S. Secretary of State Henry A. Kissinger says in a speech in Lusaka, Zambia, that black majority rule must be achieved in Rhodesia within two years. He announces a stiffening of U. S. economic and political sanctions against Salisbury.

Sept. 24, 1976: Smith confers with Kissinger in South Africa and announces agreement to surrender white power to blacks in two years.

Oct. 21, 1976: Opening of talks in Geneva between Smith's government and Rhodesian black nationalist leaders. Talks eventually collapse over failure to agree on date for transfer of power to a black government and on cabinet posts to be retained by whites in the transition government.

Sept. 1, 1977: Britain and United States unveil seven-point peace plan leading to black majority rule by the end of 1978. SMith dismisses the proposals.

Sept. 24, 1977: The five key African states supporting the Rhodesian black nationalists approve the Anglo-U. S. plan.

Nov.24, 1977: Smith announces agreement to elections based on majority rule if black nationalists will agree to safeguard white interests constitutionally. African National Council leader Bishop Abel Muzorewa, Sithole and Chief Jeremiah Chirau join Smith for constitutional talks.

Feb. 15, 1978: Smith announces agreement with Muzorewa, Sithole and Chirau for universal suffrage elections leading to black rule with constitutional safeguards for whites.