Warren Christopher, the former secretary of State and eminence grise of the Democratic Party whose achievements in a wide-ranging public career include brokering the Bosnian peace agreement for the Clinton administration and leading an independent investigation of the Los Angeles Police Department that brought important reforms after a notorious police beating, has died. He was 85.

Christopher died Friday at his home in Los Angeles of complications from bladder and kidney cancer, said Kathy Osborne, his executive assistant at the law firm O'Melveny & Myers, where Christopher was a senior partner.

Called "the best public servant I ever knew" by President Carter, Christopher was known as a skilled negotiator whose tenacity, decorum and discretion were prized traits in crises.

As deputy secretary of State in the Carter administration, he played a pivotal role in securing the release of the Americans held hostage in Iran. As secretary of State for President Clinton, he kept warring parties at the table during the Dayton, Ohio, peace talks between the Bosnians and Serbs. After returning to private life, he served as Vice President Al Gore's emissary in the Florida vote recount that settled the disputed 2000 presidential election.

When Los Angeles fractured along racial lines after the 1991 police beating of Rodney G. King, Christopher was drafted to head the Independent Commission on the Los Angeles Police Department, which quickly became known as the Christopher Commission. Under his leadership, the 100-day inquiry produced a plan for the department's overhaul, including a strong call to replace Chief Daryl F. Gates, who later resigned.

The unity of the commission — which included members selected by Gates and his main antagonist, Mayor Tom Bradley — was in large measure a testament to its self-effacing chairman and his quiet diplomacy.

"Most talking is not glamorous," he once said. "Often it is tedious. It can be excruciating and exhausting. But talking can also tame conflict, lift the human condition and move us close to the ideal of peace."

Unfailingly courteous and calm, Christopher was known for keeping his emotions in check under the most trying circumstances. He sometimes told the story of the time he was a deputy attorney general in the Lyndon Johnson administration and the president called him in the middle of the night. He lunged for the phone and broke his toe but concealed the accident — and the throbbing pain — for the entire conversation.

That was a small reminder of the stamina that went on public display during his tenure as secretary of State, when Christopher logged more miles in pursuit of American objectives than any previous secretary in a four-year period. That record was built in part by his efforts to revive Middle East peace talks, which led him to make 35 trips to Israel and 24 to Syria.

But the lean, sober-faced diplomat was often portrayed by critics as weak and ineffectual. During his four years in the Clinton Cabinet he was faulted by Washington insiders for failing to articulate a coherent vision for American foreign policy in the post-Cold War era.

One of his sharpest critics, former national security advisor Zbigniew Brzezinski, said Christopher's weakness was his desire to "litigate issues endlessly, to shy away from the unavoidable ingredient of force in dealing with contemporary international realities and to have an excessive faith that all issues can be resolved by compromise." Skeptics called him "Dean Rusk without the charisma," comparing him to the Johnson-era secretary of State who was also known for his low-key style.

Gore, however, offered a different vision of Christopher, calling him "one of the great statesmen of our era." Beginning with the Carter era and during his tenure under Clinton, Christopher developed human rights "as a pillar of our working diplomacy," Gore said in a statement Saturday. "He methodically reviewed every element of American diplomatic practice, and by the time he was finished, human rights were welded, bolted and wedged into the core where they remain to this day."

After every stint in public service, Christopher returned to O'Melveny & Myers, the influential, old-line Los Angeles law firm where he began his career six decades ago and which he eventually led as chairman. He was credited with expanding the firm's international operations as well as its civic engagement, especially through pro bono projects.

Warren Minor Christopher, the fourth of five children, was born Oct. 27, 1925, in Scranton, N.D., a prairie town settled at the turn of the 20th century by Scandinavian and German immigrants.

His mother, Catherine, helped the needy, including hobos who found their way to the family's doorstep from freight cars that ran near their home. She always declined the men's offers to work in exchange for supper because she believed "that our relatively good fortune was something to be shared, not bartered," Christopher wrote in "Chances of a Lifetime," his 2001 memoir.

His father, Ernest, managed the local bank and was well-liked despite having what Christopher described as the demeanor of "a taciturn Norwegian Lutheran." He said later that he was profoundly affected by his father's stories about how the Depression ruined many farmers in town and his struggles to resist foreclosing on their mortgages. Christopher said the strains of trying to keep the bank afloat while many of his friends and neighbors went under led to his father's incapacitating stroke in 1937 when he was only 49. Ernest Christopher died five years later.

What he learned from his father was that "you do not have to make a public display of compassion to be a compassionate person," Christopher wrote in his memoir. "The human scenes I witnessed in the flat, dry North Dakota plains while at my father's side may account more than anything else for the tilt of my social and political concerns in the direction of the unfortunate."

Catherine Christopher moved the family to California in 1939 and went to work as a salesclerk. Warren earned money delivering papers for the Hollywood Citizen-News and excelled on the debate team at Hollywood High School.

At 16 he entered what is now the University of Redlands on a debate scholarship, but transferred after a year to the Naval Officer Program at USC. He graduated in 1945 as an ensign. He served on an oil tanker in the Pacific theater as World War II was winding down.