After a brief career in Indian Civil Services , he took up teaching and research in 1984 .
Sen took his bachelor 's and master 's degrees in history from St. Stephen 's College , Delhi and also pursued his PhD there .
After a brief career in Indian Civil Services , Sen took up teaching and research in 1984 .
Sen took his bachelor 's and master 's degrees in history from St. Stephen 's College , Delhi and also pursued his PhD there .