Students on campus read about Birgeneau's announcement on the college website. There was much praise from colleagues.
"He's been able to continue to retain the faculty and build the quality of the faculty and that's really the core of the university," said Karl Pister, Ph.D., from UC Berkeley.
The student body president said the chancellor brought inclusion to the university.
"He was really an advocate for underrepresented minority students and undocumented students. I think most recently his Middle Class Access Plan, set the precedent for the entire country," said Vishalli Loomba, the student body president.
That plan makes it easier for middle class families to afford Cal.
Birgeneau said he stayed longer than expected because he wanted to sort out the impact California's economic crisis has had on the university.
However, some question whether the Nov. 9 clash between students and campus police prompted his decision to leave. He's had security outside his home even before that incident. Birgeneau initially sided with campus police, but then changed his mind. He wrote: "These videos are very disturbing. The events of last Wednesday are unworthy of us as a university community."
"No chancellor could survive as chancellor on a campus after doing what he did to his own students. This is undoubtedly a major part of his legacy and we are very glad to see him go," said Yvette Felarca, a former Cal student.
His friend, Pister, is a former UC Santa Cruz chancellor.
"You tend to personalize that when you shouldn't, but it's inevitable you will. I think Bob really felt really bad about the way he was treated by some of his detractors and by the press," said Pister.
Birgeneau also wants to see the construction of the Cal Memorial Stadium completed. It's scheduled to open in September.