"He wasn't cruel--he painted what he saw," remarked a robust model for one of Lucien Freud's nude portraits. Freud, who died in London on July 20, at age 88, painted raw and unsettling images of people he knew, often naked with skin of a pasty hue.

The German-born artist, a grandson of psychoanalyst Sigmund Freud, helped redefine portraiture in the post-war years.

"Freud...comes at you in the same ways every time; flesh for flesh's sake; physical fervor; psychic frayed nerves," writes critic Jerry Saltz.

Considered by some to be one of the greatest painters of the 20th and 21st centuries, Freud became revered for his uncompromising realism. His portrait of an enormously overweight nude woman sleeping on a couch sold in 2008 for $33.6 million.

"I paint people," Freud said, "not because of what they are like, not exactly in spite of what they are like, but how they happen to be."