Former U.S. Secretary of Defense Donald Rumsfeld has died at the age of 88, his family announced Wednesday.

Rumsfeld served as secretary of defense from 1975-77 under Gerald Ford, and again from 2001-06 under George W. Bush.

Rumsfeld was also a three-term congressman from Illinois (1963–69); director of the Office of Economic Opportunity (1969–70); counsellor to the president (1969–73), the U.S. permanent representative to NATO (1973–74); and White House chief of staff (1974–75).

Bush hailed his “steady service as a wartime secretary of defense — a duty he carried out with strength, skill, and honor.”

He made a brief run for the 1988 Republican presidential nomination, a spectacular flop that he once described as humbling for a man used to success at the highest levels of the government, including stints as White House chief of staff, U.S. ambassador and member of Congress.

For all Rumsfeld’s achievements, it was the setbacks in Iraq in the twilight of his career that will likely etch the most vivid features of his legacy.

Nine months into his second tour as defense secretary, on Sept. 11, 2001, suicide hijackers attacked the World Trade Center in New York and the Pentagon, thrusting the nation into wars for which the military was ill-prepared. Rumsfeld oversaw the U.S. invasion of Afghanistan and toppling of the Taliban regime. Frequently presiding at televised briefings on the war, Rumsfeld became something of a TV star, applauded for his blunt talk and uncompromising style.

By 2002 the Bush administration’s attention shifted to Iraq, which played no role in the Sept. 11 attacks. The war effort in Afghanistan took a back seat to Iraq, opening the way for the Taliban to make a comeback and prevent the U.S. from sealing the success of its initial invasion.

The U.S.-led invasion of Iraq was launched in March 2003. Baghdad fell quickly, but U.S. and allied forces soon became consumed with a violent insurgency. Critics faulted Rumsfeld for dismissing the pre-invasion assessment of the Army’s top general, Eric Shinseki, that several hundred thousand allied troops would be needed to stabilize Iraq.

Rumsfeld twice offered his resignation to Bush in 2004 amid disclosures that U.S. troops had abused detainees at Iraq’s Abu Ghraib prison — an episode he later referred to as his darkest hour as defense secretary.

Not until November 2006, after Democrats gained control of Congress by riding a wave of antiwar sentiment, did Bush finally decide Rumsfeld had to go. He left office in December, replaced by Robert Gates.

Rumsfeld is survived by his wife, Joyce, three children and seven grandchildren.

The Associated Press contributed to this report.