George Deukmejian, a two-term Republican governor of California, at his office in the Capitol in 1987. (Walt Zeboski/AP)

George Deukmejian, a two-term Republican governor of California who championed low taxes and small government but crossed party lines to sign a ban on military-style assault weapons, died May 8 at his home in Long Beach, Calif. He was 89.

His daughter Leslie Deukmejian Gebb confirmed the death but did not cite a precise cause.

Mr. Deukmejian (pronounced duke-MAY-zhee-an) was a California state assemblyman, senator and attorney general before being elected governor in 1982. As the highest elected official in America’s most populous state, he occupied an office that launched predecessors Earl Warren and Ronald Reagan to national political prominence.

Yet he shunned the media spotlight, avoiding appearances on talk shows that helped make peers such as Mario Cuomo — the liberal governor of New York elected the same year as Mr. Deukmejian — powerful forces in debates over the scope and role of government.

Instead, he focused on righting California’s finances and strengthening its prison system, maintaining an emphasis on public safety that had led him to reinstate the death penalty and pass “use a gun, go to prison” legislation as a lawmaker in Sacramento.

Mr. Deukmejian, far right, with his wife and President George H.W. Bush at a California Chamber of Commerce dinner in 1990. (Barry Thumma/AP)

Known as the “Iron Duke” for his severe approach to fiscal conservatism, he became one of the most popular governors in the state’s modern history, surpassing Reagan in public approval even while facing occasional ridicule for his bureaucratic demeanor.

Mr. Deukmejian called for “a common-sense approach to running government” and took office promising to trim state spending and eliminate California’s $1.5 billion deficit, inherited from Democrat Jerry Brown, without raising taxes. Buoyed by an economic surge that lifted tax revenue, he did just that, and in a State of the State address, he declared that he had “taken California from I-O-U to A-OK.”

To Republicans, he was seen as a hero for standing up to the state’s Democratic legislators, who dubbed him “Dr. No” for the 2,298 bills he vetoed over eight years, a record that still stands.

His opposition to spending did not extend to the state’s prison system. He oversaw what George Skelton, a longtime political columnist for the Los Angeles Times, described as “the biggest prison construction program in the nation’s history, spending $3.3 billion to build eight penitentiaries — going from 12 to 20 — and making seven major additions to existing institutions.”

The number of felons in the state, Skelton wrote, tripled to nearly 97,000 during Mr. Deukmejian’s tenure, “leaving cells more overcrowded than when Deukmejian began the building.”

The project was part of an interest in law and order that Mr. Deukmejian, the son of Armenian immigrants, traced to the Armenian genocide, in which 1.5 million Armenians were killed by Ottoman Turks during World War I. An aunt was among family members killed in the violence, stories of which spurred Mr. Deukmejian to lead a 1986 divestment effort against companies that did business in apartheid South Africa.

Mr. Deukmejian also transformed the state judiciary, appointing hundreds of conservative prosecutors and judges, including on the California Supreme Court. He appointed five of the court’s seven members, partly through a successful voter-initiative campaign that ousted liberal judicial activists such as Rose Bird, whom Brown had appointed chief justice.

“His appointees pushed the California judiciary to the right for 20 or 30 years, on issues including criminal justice, the death penalty and business regulation,” said Ethan Rarick , a former political journalist and author of “California Rising: The Life and Times of Pat Brown.”

Yet while the Republican Party veered further to the right, Rarick said, Mr. Deukmejian demonstrated flashes of pragmatism and moderate policymaking, especially toward the end of his term. He worked with Democrats to pass an $18.5 billion transportation package funded by a gas-tax increase, and he approved a state-subsidized health insurance program for people suffering from AIDS, cancer and other serious illnesses.

Perhaps most significantly, he signed legislation in 1989 that made California the first state to ban military-style semiautomatic weapons. Mr. Deukmejian said he hoped the bill would help “save innocent lives,” citing the deaths of “five beautiful young children” at a Stockton elementary school earlier that year. The children were killed by a gunman with an AK-47 assault rifle.

Courken George Deukmejian Jr. was born in Menands, a New York village that neighbors Albany, on June 6, 1928. His father ran a rug business, and his house was situated next to the fire and police stations, where officers sometimes drove him to kindergarten in their motorcycle sidecars.

Mr. Deukmejian was involved in his first major political effort in 1948, when he volunteered for the presidential campaign of New York’s Republican governor, Thomas Dewey. He received a bachelor’s degree in sociology one year later from St. Bernardine of Siena College (now Siena College), a Franciscan school in Loudonville, N.Y.

In 1952, he graduated from law school at St. John’s University in New York City. He served in the Army Judge Advocate General’s Corps in Paris and subsequently moved to Southern California, where he worked for the oil company Texaco and in 1957 married Gloria Saatjian, also an Armenian American.

In addition to his wife, of Long Beach, survivors include three children, Deukmejian Gebb and Andrea Deukmejian Pollak, both of Long Beach, and George Deukmejian of Sacramento; and six grandchildren.

Mr. Deukmejian was elected to the State Assembly in 1962 and, during his 16 years as a legislator, wrote more than 100 bills. He was elected state attorney general in 1978. Four years later, he narrowly defeated Tom Bradley, the Democratic mayor of Los Angeles, to become governor.

The two candidates battled again in 1986, when Mr. Deukmejian ran away with 61 percent of the vote. He declined to run a third time, and was succeeded in 1991 by Republican Pete Wilson.

Until retiring in 2000, Mr. Deukmejian worked as a partner in the L.A. office of Sidley & Austin. Life outside of politics had its perks, he told the Times.

“You get up every morning and you don’t have to worry about 30 million people, deal with 120 legislators, deal with the press,” he said. “It took me about five minutes to adjust to a private, normal life without all those concerns and headaches.”