Joseph Robinette "Beau" Biden III, the son of Vice President Biden and former state attorney general of Delaware, died Saturday after battling brain cancer for several years.
Mr. Biden, 46, had been admitted recently to Walter Reed National Military Medical Center in Washington as he fought the cancer, a battle that his father largely kept private in the last weeks.
"The entire Biden family is saddened beyond words. We know that Beau's spirit will live on in all of us - especially through his brave wife, Hallie, and two remarkable children, Natalie and Hunter," the vice president said in a statement released Saturday night.
Mr. Biden, a major in the Delaware Army National Guard's Judge Advocate General Corps, became one of his state's most popular public figures and had been considered the frontrunner for the 2016 race to become governor, but in August 2013 he checked into one of the world's most renowned cancer treatment centers, Texas Medical Center, in Houston to begin his fight with the disease.
A University of Pennsylvania graduate, Biden earned a law degree from Syracuse University. He clerked for a federal judge in New Hampshire before joining the U.S. Justice Department from 1995 until 2002, including five years as a federal prosecutor in Philadelphia.
He became a national political star in 2008 after delivering a stirring introduction of his father at the Democratic National Convention in Denver. A little more than a month later he deployed to Iraq and served there for one year - except for a trip home in January 2009 to see his father take the oath of office as vice president.
In Denver seven years ago, Mr. Biden told the tragic family story that became the emotional foundation for his father's 36 years of service in the Senate and the last 61/2 years as vice president.
Shortly after winning his Senate race, in December 1972, Joe Biden received a call while in Washington interviewing staff. His wife, Neilla, and three children had been in a car crash on the way home from purchasing the family Christmas tree. His wife and daughter had died, and his sons, Beau and Hunter, were clinging to life. Still a few days shy of turning 30, Joe Biden raced home to Wilmington and considered never taking the oath of office.
Through the support of other senators, he agreed to be sworn in the next month, at the hospital bedside of Beau and Hunter. Eventually venturing to Washington, he decided that he would take the train every morning from Wilmington and return every night.
"As a single parent, he decided to be there to put us to bed, to be there when we woke from a bad dream, to make us breakfast, so he'd travel to and from Washington, four hours a day," Mr. Biden told the Denver crowd on Aug. 27, 2008.
President Obama said he and first lady Michelle Obama were grieving alongside the Biden family.
"Michelle and I humbly pray for the good Lord to watch over Beau Biden, and to protect and comfort his family here on Earth," Obama said.