[5] He did his apprenticeship in 1962 at an old line cloak-and-suit manufacturer, Dan Millstein,[6] and spent five years designing at other New York City shops.

[8][9] He became a protégé of Baron de Gunzburg,[9] who introduced him to the New York elite fashion scene before he had his first mainstream success with the launch of his first jeans line.

[10] In 1998, Klein participated in a celebrity reading of "The Emperor's New Clothes," for The Starbright Foundation to benefit ill children.

[13] They have a daughter, television producer Marci Klein,[14] who is best known for her work on NBC's Saturday Night Live and 30 Rock.

[13] In September 1986, Klein married his assistant Kelly Rector in Rome while they were on a buying trip in Italy.

[18] He hosted friends such as artist Andy Warhol, Studio 54 owner Steve Rubell, Fashion designer Chester Weinberg, and media mogul David Geffen.

"[20] In 2003, Klein bought an ocean-front estate in Southampton, New York, on Long Island and demolished it to build a $75 million glass-and-concrete mansion.