Welcome to the A to Z of Historical Blunders, the show that reminds us about the dangers of history repeating itself.

This week, our dial will oscillate between 16^th century England and early 19^th century Europe and compare the fates of an imprisoned ‘would be’ monarch and a beleaguered emperor who put too much trust in the art of cryptography. Both Mary Queen of Scots and Napoleon Bonaparte were victims of a false sense of security.  All encryption did was to buy them a little time, before their secrets were disclosed.

My guests this week are Michael Carragher and Dr Brian Cogan.

Like myself, Michael Carragher is a curmudgeonly old history teacher. He studied at Trinity College Dublin, the University of Arkansas and the University of Birmingham, where he specialised in First World War Studies. Michael has published both fiction and history, notably A World full of places and other stories; Motorcycles and British victory 1914-1918; and, The man who saved Paris: Roger West’s ride 1914.

Electronic Engineer, Brian Cogan did his undergraduate degree and master’s in UCD, and his Ph.D. in Trinity College. Brian also taught a master’s course in Renewable Energy in Maynooth University. He currently teaches in Dublin Institute of Technology in the Department of Electronic Engineering. He has published in several academic journals. Brian has a lifelong interest in the history of science and mathematics.