John Michael Derrick was the son of Thomas Derrick, an English Catholic artist linked with the Catholic artistic and literary circles of the early decades of the 20 century, and brother of the writer Christopher Derrick. He became Assistant Editor of the Tablet in 1938, where he worked for Douglas Woodruff until his death in 1961. The Tablet credits him with having an & encyclopedic knowledge of matters ecclesiastical whose talents heavily complimented those of his Editor.