Robert Baker Aitken, one of the first American masters of Zen Buddhism and a community activist, died Thursday at Straub Hospital in Honolulu. He was 93.

He was the founder, leader and teacher of Honolulu Diamond Sangha, an international Zen Buddhist society, and given the title of "Roshi," meaning "elder master." Aitken also had a long association with peace and social justice movements in Hawaii. He wrote 13 books.

Aitken was born in Philadelphia in 1917 but grew up in Hawaii and California. His introduction to Zen Buddhism came during his years of internment in Japan, following his capture as a civilian on Guam during World War II, according to a news release from the Diamond Sangha.

After he was freed, Aitken resumed his studies at the University of Hawaii, graduating in 1947 with a degree in English literature, and later a master’s degree in Japanese studies.

In the Robert Baker Aitken Papers, part of the University of Hawaii at Manoa Libraries, Aitken wrote, "I took part in the Mother’s Day Walk for Peace in 1952 with Marion and John Kelly, an anti-nuclear protest, and the first of many demonstrations. During the Vietnam War I was active as a resister and draft counselor."

He was close to, among others, political science professor Oliver Lee, whose denial of tenure triggered a protest in 1967. "I took part in the Bachman Hall sit-in as part of the faculty contingent," Aitken wrote. "In 1972, I walked around the island for peace and social justice in a group led by Jim Albertini and John Wittick."

With his second wife, Anne Hopkins Aitken, he founded the Sangha in 1959 and brought masters from Japan to instruct the group.

The Diamond Sangha flourished, especially after he received sanction to teach independently in 1974. Today the organization is part of an international network of affiliated groups, the release said. Its main temple in Hawaii is Palolo Zen Center in Honolulu; branches include Maui Zendo and Hilo Zen Circle.

His publications include "Taking the Path of Zen," "The Mind of Clover" and "The Gateless Barrier."

Aitken’s first marriage in 1947 was to Mary Laune of Honolulu. He is survived by their son, Thomas Laune Aitken, and three granddaughters.

A memorial service will be held at 10 a.m. Aug. 22 at the Palolo Zen Center.