The decorated soldier's career was blemished, as he later acknowledged, by a 2003 speech to the United Nations claiming evidence that Iraq's Saddam Hussein had weapons of mass destruction. The false assertion was used to justify the U.S.-led invasion of Iraq.

After starting as a second lieutenant, a rank earned as a Reserve Officer Training Corps student at City College of New York, Powell served in Vietnam, West Germany and South Korea before being put in charge of the 1990 Gulf War as chairman of the joint chiefs of staff.

President Joe Biden said in a statement Monday that "Colin embodied the highest ideals of both warrior and diplomat" and that "having repeatedly broken racial barriers," he was "committed throughout his life to investing in the next generation of leadership."

In the allied effort to help Saudi Arabia and Kuwait defend against Iraq, Powell developed what came to be known as the Powell Doctrine: It called for using overwhelming force, such as "shock-and-awe" battle tactics, to assure victory and minimize casualties once diplomatic solutions proved unworkable. He styled himself the "reluctant warrior."

Admired for his mix of military discipline and sunny optimism, Powell was often urged to run for president. Tall, solidly built, with salt-and-pepper hair and an easy smile, he represented to many an American ideal of hard work and equal opportunity.

"It will be impossible to replace Gen. Colin Powell," Lloyd Austin, a retired general who is now the first Black U.S. defense secretary, said in a tweet. "He was a tremendous personal friend and mentor to me, and there's a hole in my heart right now as I think about his loss."

Secretary of State Antony Blinken said of Powell's time in that role, "He gave the State Department the very best of his leadership, his experience, his patriotism. He gave us his decency, and the State Department loved him for it."

The author of four books about his career and thoughts, Powell argued that he was part of a new generation of accountable leaders.

"Many of my generation, the career captains, majors, and lieutenant colonels seasoned in [Vietnam], vowed that when our turn came to call the shots, we would not quietly acquiesce in halfhearted warfare for half-baked reasons that the American people could not understand," he wrote in "My American Journey," published in 1995.

Such idealism proved elusive, however, in the 2003 Iraq War to oust Saddam. As secretary of state, Powell was given the task of justifying an allied invasion. His speech to the United Nations included pictures he said were of mobile arms laboratories. Based on assurances from the director of the Central Intelligence Agency, he asserted there was "no doubt" that Saddam had hidden chemical and biological weapons.

But the following year, Powell told Congress that the evidence was "wrong," and the speech "a blot" on his record.

"It was painful," he told interviewer Barbara Walters in 2006. "It is painful now."

Powell had two other blots on an otherwise lauded record. In the first, he was assigned to investigate the 1968 U.S. massacre at My Lai and found no wrongdoing. And as President Ronald Reagan's national security adviser, he was part of an administration that illegally traded arms for hostages in what became known as the Iran-Contra scandal. He was not personally implicated in either case.

After serving as the top U.S. official in the Gulf War, he was considered as a Republican vice-presidential candidate in the 1992 campaign and was urged to run against President Bill Clinton in 1996. He declined but actually won the GOP New Hampshire primary based on write-in votes.

In 2000, he again declined to run. The winner, George W. Bush, appointed him secretary of state, a post from which he resigned in 2004 when the evidence on Iraq's weapons of mass destruction was shown to be false. His resignation prompted some to lament the loss of a moderating voice within the administration and others to urge his successor to play a bigger role in policy decisions.

Bush, in a statement Monday, called Powell "a great public servant."

"He was such a favorite of presidents that he earned the Presidential Medal of Freedom -- twice," Bush said. "He was highly respected at home and abroad. And most important, Colin was a family man and a friend."

After his retirement, Powell leaned more liberal, quietly campaigning against the nomination of John Bolton to be ambassador to the UN. He supported affirmative action and criticized the Bush administration on its treatment of detainees at the Guantanamo Bay detention facility and its handling of impoverished victims of Hurricane Katrina. In 2008 and 2012, he endorsed Barack Obama, a Democrat, for president. He supported Hillary Clinton over Donald Trump in 2016 and Biden over Trump in 2020.

Powell was awarded the Medal of Freedom, the highest U.S. civilian decoration.

After leaving public service, Powell joined Kleiner Perkins Caufield & Byers, a Silicon Valley venture capital firm, as a "strategic limited partner" and served on corporate boards, living a lush Manhattan life.

Colin Luther Powell was born on April 5, 1937, in New York City to Maud Arial McCoy and Luther Theophilus Powell, a shipping clerk whose ancestors were African and Scottish.

He received a bachelor's degree in geology from the City College of New York in 1958 and an MBA degree from George Washington University in 1971, after his second tour in Vietnam.

In 1962, while on patrol in South Vietnam as one of 16,000 military advisers, Powell was wounded by a punji-stick booby trap and was awarded a Purple Heart. He also won a Bronze Star and later the Soldier's Medal for rescuing comrades after a helicopter crash.

After studying at the Army War College and a serving in Korea as a battalion commander, Powell got a staff job at the Pentagon and was promoted to one-star general in charge of a brigade of the 101st Airborne Division. In 1983, he was an aide to Secretary of Defense Caspar Weinberger in the first Reagan administration. He later served as an aide to Reagan's national security adviser Frank Carlucci before Reagan gave him Carlucci's job. In that role, he advised Reagan on summit meetings with Soviet President Mikhail Gorbachev as the Cold War was ending. Reagan made him chairman of the joint chiefs in 1989.

Powell retired from the army in 1993 with the rank of four-star general.

Powell married Alma Vivian Johnson in 1962. The couple had three children: Michael, who was chairman of the Federal Communications Commission from 2001 to 2005, Linda, an actress, and Annemarie.

Biden described Powell in his statement as a friend "who was easy to share a laugh with." He said "he could drive his Corvette Stingray like nobody's business -- something I learned firsthand on the race track when I was vice president."

With assistance from Bloomberg's Jenny Leonard and Nick Wadhams.