Immediately after graduating he obtained a post at his old school in Pengam but soon moved to Tettenhall College , Wolverhampton . In 1895 he was appointed the first headmaster of the new county school in Bethesda, Caerns. , a post which he held until his retirement in 1933 . Religion was a major interest. He was a deacon at Bethesda chapel (Congl.) and then at Bethania , Bethesda . He contributed a great deal to the work of the Sunday school and he was one of the editors of the new, modern handbooks for children published by the Union of Welsh Independents . He was one of the secretaries of the Union from 1924 to 1927 and Chairman 1944-45 . He was general secretary of Bala-Bangor College from 1932 to 1951 and over a period of some 20 years he compiled a biographical dictionary of all the professors and students of the college . There is a copy of the work at N.L.W.

He m. twice; (1) in 1897 Selina , dau. of John Evans , Minafon , Blackwood, Mon. , and (2) in 1929 her sister Mary . He had a dau. and 3 sons. D.J. Williams was an unassuming man whose shyness concealed his great ability and his acquaintance with many prominent figures, but he left his mark heavily on the community in the Ogwen valley . He d. 1 Oct. 1951 and was buried in Coetmor cemetery , Bethesda .