Sir David Hughes Parry joined the LSE Law Department in 1924, following four years as a lecturer in law at the then University College of Wales, Aberystwyth. In 1928 he became Reader and in 1930 he succeeded Edward Jenks as Professor of English Law. He was the founding director of the Institute of Advanced Legal Studies from 1947 to 1959. He was Vice-Chancellor of the University of London from 1945 to 1948 and Chairman of the University Court from 1962 to 1970. Throughout his time at the University of London he remained closely connected to his native Wales. He played a significant role in Welsh public life, most notably chairing the committee on the legal status of the Welsh language from 1963-1965. The committee produced a report that subsequently led to the Welsh Language Act of 1967, which established a principle of equality of English and Welsh. He was knighted in 1951 and died at his home in North Wales on 8 January 1973.