Charles was born in Kenya, qualified in Cape Town, South Africa, with postgraduate training in Paediatrics in Manchester and London, United Kingdom. As a lecturer at University of Oxford, he returned to Kilifi Kenya in 1989, to help set up an unit to study severe malaria in African children. Thereafter he spent 2 years as a Post-doctoral fellow at Johns Hopkins, USA; studying mechanisms of brain damage in central nervous system infections. He completed his training in Paediatric Neurology at Great Ormond Street Hospital, UK. In 1998 he was awarded a Wellcome Trust Senior Clinical Fellowship at University College London, to return to Kilifi, to study CNS infections in children. He has published on a wide variety of subjects concerning sick children in tropical countries. In 2011 he took up a professorship in Psychiatry at the University of Oxford to concentrate of neurological and mental illness disorders in children living in Africa.