Tuesday 24 January 2017

Published 21/02/2016 | 23:49

Former investment banker and Clongowes boy O'Callaghan (46, right) was a high-flying technology gazillionaire, building up Riverdeep and then Houghton Mifflin into one of the world's biggest online publishers before everything came unstock during the financial crisis.


Please sign in or register with Independent.ie to access the Rich List articles.

Sign In

  • Go To

Read More

Also in Business