TAIPEI (Taiwan News) — Chen Yun-tung (陳運棟), a long-serving community leader who dedicated his life to the study of Hakka culture and history, has died, aged 91.

Chen, whose name is Romanized as Ciinˇ Lun-dung to represent Hakka pronunciation, was described by his son as a man who worked hard to carry forward the Hakka spirit, per CNA. Chen had been in poor health for some years, and died during an afternoon nap.

Chen was born in Miaoli, and was a primary and high school teacher. He also served on the Hakka Affairs Council under the Cabinet. Chen published more than 40 books, including a compendium recording research about Hakka culture in 1967.

Hakka are a subgroup of the Han Chinese ethnic group whose ancestral homes are found in Taoyuan, Hsinchu, Miaoli, Pingtung, and Kaohsiung, as well as in multiple provinces in China. The worldwide Hakka population sits at an estimated 80 million.