Justice Ruth Bader Ginsburg on Monday paid tribute to Herma Hill Kay, her longtime friend and former dean at The University of California, Berkeley School of Law who died in 2017, by speaking on campus as the inaugural lecturer in a series named in Kay’s honor.

Ginsburg, who met Kay at a conference on women and the law at Yale Law School in 1971, said that shortly thereafter Kay became her “best and dearest working colleague.” The two co-authored a 1974 casebook on sex discrimination, and Kay testified at Ginsburg’s 1993 confirmation hearing for her post on the U.S. Supreme Court while she was serving as Berkeley Law dean.