Alongside being a Visiting Professor of the Department of Mathematics at the London School of Economics, I am Emeritus Professor in Pure Mathematics in the Faculty of Mathematics, Computing and Technology at the Open University, having retired from the OU in 2009. My main areas of interest are the History of Mathematics (British history from 1600, especially the period 1840-1940 and the history of Gresham College, and the history of graph theory and combinatorics) and Graph Theory (graph colourings, especially edge-colourings).
In addition to my Open University commitments, I am Emeritus Professor of Geometry at Gresham College in London, giving lectures to the general public - all my lectures there can be watched on the Gresham College website. I am also a former Fellow in Mathematics at Keble College, Oxford University, and now teach part-time for Pembroke College, Oxford. Currently I am President of the British Society for the History of Mathematics.