Jeffrey Mass

Jeffrey P. Mass, a Stanford University professor who was a leading authority on medieval Japanese history, died of cancer March 30 at Stanford Medical Center. The Palo Alto resident was 60.

Colleagues said Professor Mass' contributions to Western understanding of early Japanese history were enormous and included writing more books on the subject -- 10 -- and teaching more doctoral students in the field than any other Western scholar.

"Jeff virtually created the field of early Japanese history single-handedly, " Caroyln Lougee Chappell, chairwoman of the Stanford history department, said.

Professor Mass was especially interested in Japan's first warrior government, known as the shogunate, the nation's early judicial system and the evolution of inheritance and kinship during its medieval era.

"His work was innovative and sometimes controversial, but always thoroughly grounded in documentation and deep, deep research," Stanford history professor Peter Duus said.

A native of New York City, Professor Mass earned a bachelor's degree from Hamilton College in 1961 and a master's degree in history from New York University four years later. He earned a doctorate in the subject from Yale University in 1971 and joined the Stanford faculty in 1973.