In September 1969, John married Janet Talfan Davies, daughter of Alun Talfan Davies QC, a leading Welsh lawyer.John (1974) pp. 63, 109 John and Jan had four children (Kathryn, Lucy, Anna and David) and as of 2016, eleven grandchildren (Emily, Rebecca, Sam, Tom, Ben, Anna, Edward, Will, Gwen, Ella and Charlotte); John and his wife are now separated.
