Donda West, mother of Kanye West and former chairwoman of Chicago State University's English department, has died, a spokesman for the rapper said. She was 58.

Donda West died Saturday night in Los Angeles, said the spokesman, who asked for anonymity because not all family members had been notified. "The family respectfully asks for privacy during this time of grief," the spokesman said. A cause of death has not been released. Donda West was known for the strong bond she shared with her son, by whose side she was often seen at parties and award shows.

Kanye West, 30, often spoke of his close relationship with his mother, who raised him alone after her husband left when Kanye was 3. She was the inspiration for the song, "Hey Mama," on Kanye West's 2005 album "Late Registration," in which he sings: "Hey Mama, I wanna scream so loud for you, cuz I'm so proud of you ... I appreciate what you allowed for me. I just want you to be proud of me."

Donda West frequently defended her son against critics who accused him of penning misogynistic lyrics and other purported transgressions.

"I support my baby," she said in a Chicago Sun-Times interview. "He is telling how he feels and he is speaking the truth as he sees it." Kanye West told the Associated Press in August that he and his mother worked together to devise the foundation's first program, "Loop Dreams," which helps public school students get involved in music.

"Me and my mother were discussing ways to give back and came up with the concept," he said.

Donda West worked in higher education for 31 years, before leaving academia in 2004 to help manage her son's career, according to a biography on the Kanye West Foundation's Web site.

"She was everyone's mom," Rhymefest said. "A spirit never dies, a spirit lasts forever."