- University Lecturer in the Politics and Government of Latin America, University of Oxford and Fellow, St Antony’s College, Oxford (from 1966 to 2008)
- Quondam Fellow, All Souls College (from 1966)
- Prize Fellow, All Souls College (from 1962 to 1966)
- Undergraduate, New College, Oxford (from 1959 to 1962)
- Chiefly nineteenth and twentieth century history of Colombia: caciquismo, the history of taxation, civil wars, coffee, insecurity and its economic consequences, the interaction of local and national politics, the interpretation of violence and many other themes
- Del poder y la gramática (3rd edn, Taurus: Bogotá, 2006)
- Intercambios violentos: Reflexiones sobre la violencia política en Colombia (Bogotá, 1999)
- ‘Essay on Columbian Violence’, in David Apter (ed.), The Legitimisation of Violence (London: Macmillan, 1997)
- Vida y opinions de Mr William Wills, 2 vols. (Bogotá: Banco de la Républica, 1996)
- Publications (PDF)
- Advisor in Colombia to President César Gaviria’s Consejería de Seguridad y Defensa, helping to design policies to reduce Colombia’s high levels of violence (from 1990 to 1994)
- Member, Orden Andrés Bello (Venezuela)
- Orden de Mérito (Ecuador)
- Senior Proctor, University of Oxford (from 1986 to 1987)
- Advisory editor, Latin American Monograph Series, Cambridge University Press.
- Member, South Atlantic Council.
- Corresponding Member, Colombian Academy of History.