Bromiley was born into an "active Christian family" in Bromley Cross, Lancashire, England, in 1915.[3] He had three sisters, one of whom, Lillian (1917–71), became a renowned teacher and evangelist, who worked firstly in China and then among the Chinese community in Malaysia.[3]
Bromiley returned to Tyndale Hall shortly after receiving his doctorate, becoming a lecturer in theology and, later, vice principal of the college (1946–51).[5] Whilst there he earned a second doctorate (DLitt) at Edinburgh for a thesis that was subsequently published as Baptism and the Anglican Reformers. He was awarded a further honorary doctorate (DD) by the university in 1961, in recognition of his contribution to church scholarship.[5]
Bromiley left academia to serve as Rector of St. Thomas’s Church, Edinburgh, from 1951 to 1958. In the latter year, he was appointed Professor of Church History and Historical Theology at Fuller, where he remained until his retirement in 1987.[2] He helped to launch the seminary's PhD degree programme in history, supervising several students using the Oxbridge tutorial method of one-to-one engagement.[5] An endowed chair in church history at Fuller was established in his name in 1991.