Ronald Fraser, 81, a British writer who expanded the range and depth of oral history with his elegant chronicle of the Spanish Civil War, “Blood of Spain,” died Feb. 10 in Valencia, Spain. He had cancer, said a friend, writer and filmmaker Tariq Ali.

Mr. Fraser worked as a journalist before he began writing about his adopted homeland of Spain, where he had lived since the 1950s. He artfully wove together first-person accounts to create oral histories of the people who lived through the tumultuous events of the Spanish Civil War.

Mr. Fraser’s first book about Spain, “In Hiding: The Life of Manuel Cortes” (1972), told the story of a barber who had been the socialist mayor of his village during the civil war, which lasted from 1936 to 1939.

With the help of his wife, Cortes managed to hide inside his house for 30 years, avoiding retribution by authorities loyal to Gen. Francisco Franco, who seized control of Spain after the civil war and ran the country as a military dictatorship until his death in 1975.

Only when Franco issued a general amnesty in 1969 did Cortes feel free to come out into the light of day. Because he had worn slippers for decades, he could no longer walk in a pair of shoes.

In the 1970s, Mr. Fraser began to interview hundreds of people who lived through the Spanish Civil War. An avowed leftist, Mr. Fraser took an evenhanded approach in “Blood of Spain” (1979), allowing voices from all sides of the conflict to speak freely. Critics found his book a sensitive portrait of the age, drawn with the humanity, depth and sweep of a novel.

“For nearly 40 years,” historian Bernard Knox wrote in The Washington Post’s Book World, “no Spanish voice was raised to talk about the war except the strident official voice of the regime. In this book the silence is broken; people who held their tongues in fear for decades here pour out their memories, their sorrows and fears, their judgments .”

Mr. Fraser chronicled the war in the cities and in the countryside, portraying intellectual skirmishes, battlefield casualties and families torn apart by the war, which killed hundreds of thousands of Spaniards.

“He has not only achieved an awesome feat of scholarship,” critic Eve Drobot wrote in the Toronto Globe and Mail, “he has also created an astoundingly three-dimensional chronicle of human beings in conflict.”

In one of the most affecting passages in “Blood of Spain,” Mr. Fraser presented the memories of a man who was 5 when his father, a supporter of Franco, was executed by a left-leaning Loyalist firing squad in 1938:

“We were going to spend his last night on earth with my father. . . . My father was perfectly calm. He embraced us, we sat down, we watched brother trying to walk, playing, and it made us all laugh a bit. . . . At five o’clock in the morning they came for him. As he got up to leave, he took his watch off and gave it to me.”

Ronald Angus Fraser was born Dec. 9, 1930, in Hamburg, to a Scottish businessman and an American mother. When Hitler came to power in 1933, his family moved to an estate in the English countryside, where a small army of servants ran the household.

Mr. Fraser described his privileged but emotionally bleak childhood in a 1984 memoir, “In Search of a Past: The Rearing of an English Gentleman, 1933-1945,” combining his own recollections with interviews with cooks, gardeners, nannies and other servants who helped raise him.

Mr. Fraser was a journalist before settling in Spain in 1957, helped by an inheritance from his wealthy mother.

His first marriage, to Fern Fraser, ended in divorce. Survivors include his wife of 25 years, Aurora Bosch; a son from his first marriage; and two children from other relationships.

In the 1960s, Mr. Fraser helped found the New Left Review, a British intellectual journal in which he published a series of 50 oral history interviews about the lives of the British working class. He collected the interviews in two books called “Working” in the late 1960s.

His final book, “Napoleon’s Cursed War” (2008), explored Napoleon’s half-forgotten war with Spain from 1808 to 1814, in which French forces were driven from the country by the guerrilla tactics of a shadow army of what Mr. Fraser called “rogues and troublemakers and the lawless.”