https://justthenews.com/politics-policy/henry-kissinger-dies-age-100
Henry Kissinger, titan of American Cold War foreign policy, dies at 100
He was the only person ever to simultaneously hold the posts of White House national security advisor and Secretary of State.
I think that was during the Ford years. Ford was a babe in the woods, completely unready for the office of President and needed the gravitas of Kissinger in both cabinet positions for some political power.