Fun fact: the original title of "A History of Western Philosophy" was "A History of Western Philosophy: analytics rule and continentals drool" until the editors made him drop the subtitle.
Didn't get the joke?
Like the comic says, Bertrand Russell was dismissed from his teaching position for promoting the idea of open sex outside of the context of marriage. He struggled for the following few years, even worrying that he might starve, as he had no means of work, having no skills outside of academia. Eventually he wrote "The History of Western Philosophy", which was popular among non-academics as an introduction to philosophy, and served as the majority of his income until he eventually found a teaching position again.
While the book had wide appeal, and did a great job introducing people to the philosophical problems of the time and some of the history of philosophy, it has been criticized for Russell's portrayal of certain philosophers in traditions that he wasn't so familiar with, such as Nietzsche and Hegel.