For half a century, he took on corrupt politicians, scam artists and bureaucratic bumblers. His visits were preceded by the four dreaded words: Mike Wallace is here.

Wallace took to heart the old reporter’s pledge to comfort the afflicted and afflict the comfortable. He characterized himself as “nosy and insistent.”

So insistent, there were very few 20th century icons who didn’t submit to a Mike Wallace interview. He lectured Vladimir Putin, the President of Russia, on corruption. He lectured Yassir Arafat on violence.

He asked the Ayatollah Khoumeini if he were crazy.

He traveled with Martin Luther King (whom Wallace called his hero). He grappled with Louis Farrakhan.

And he interviewed Malcolm X shortly before his assassination.

He was no stranger to the White House, interviewing his friends the Reagans … John F. Kennedy … Lyndon Johnson … Jimmy Carter. Even Eleanor Roosevelt.

Plus all those remarkable characters: Leonard Bernstein, Johnny Carson, Luciano Pavarotti, Janis Joplin, Tina Turner, Salvador Dali, Barbra Streisand. His take-no-prisoners style became so famous he even spoofed it with comedian Jack Benny.

Wallace’s death was announced on “CBS Sunday Morning.” The “60 Minutes” icon, who was a correspondent on the show for four decades, had been ill for several years.