Mark Knoller, a longtime CBS News correspondent, has died at the age of 73. His cause of death remains undisclosed, though he had diabetes and was in poor health.

According to CBS News, Knoller was remembered by friends and colleagues as a legend who served as the unofficial presidential historian and statistician for decades. “Everyone in the White House press corps knew him,” the network stated.

Knoller’s dedication to his role led him to create an extensive personal record of every presidential action, movement, and statement. He once described his work: “I keep a daily log of everything the president does… Every time he goes on vacation, every visit to Camp David.”

Tom Cibrowski, president and executive editor of CBS News, praised Knoller as “the hardest-working and most prolific White House correspondent of a generation,” noting his voice and reporting spanned eight presidential administrations.

Joining CBS in 1988, Knoller earned the nickname “the Wikipedia of the White House.” He covered presidents from George H.W. Bush to Donald Trump before leaving CBS in 2020.

The White House Correspondents Association President Weijia Jiang called him “the heart and soul of the White House press corps,” highlighting his passion, trustworthiness, and camaraderie. Colleagues consistently described him as a relentless journalist committed to factual reporting.

Knoller was born in Brooklyn, New York, on February 20, 1952. He worked at WNEW Radio and the Associated Press Radio Network before joining CBS, where he quickly became a prominent White House correspondent.