NEWPORT, R.I. — The Naval War College has released online a trove of World War II information in a war diary kept daily by Adm. Chester W. Nimitz and his staff as the U.S. battled Japan.

The more than 4,000 pages can be accessed at www.usnwc.edu/graybook.

War College historian Douglas Smith said that it’s the most authoritative source on the war in the Pacific theater.

Nimitz, commander in chief of the Pacific Fleet, died in 1966. He graduated from the War College in Rhode Island and lectured there several times.

The diary was declassified in 1972 but was relatively inaccessible at the Naval History and Heritage Command.

Its entries begin Dec. 7, 1941, the day Japan attacked Pearl Harbor, and go to August 1945, shortly before the Japanese surrendered.