Born in a small cottage between Derbyhaven and Hango Hill, Joseph Davidson Qualtrough was elected MHK for Castletown at a by-election in 1919. He remained a member of the House for the rest of his life, and in 1937 he was elected as Speaker, an office he held for twenty three years.
Qualtrough strove for increased independence for the Island, especially in financial matters. He chaired the Committee for Constitutional Reform, and was the first chairman of the Finance Committee set up as a result of a 1920 meeting with the Home Office. As Speaker he was a champion of the Island’s campaigns for further constitutional reform and a greater degree of responsibility for its own internal affairs.
As an MHK he was chairman for many years of the Publicity Board, the Council of Education, the Electricity Board and the Noble's Hospital Management Committee. Concerned with advancing social reform, in 1921 he succeeded in devising a national housing scheme, and a year later he was involved in the development of winter works schemes.
J.D. Qualtrough was a Manx speaker and a very musical man, serving as Chairman of the Manx Music Festival. He was knighted in 1954.