This book tells the extraordinary story of how in the mid twentieth century, in a well-developed European country, a mathematically solid system of geometry was altered to such an extent that more than one million students were taught foundationally flawed geometry over more than a quarter of a century. The almost unbelievable situation came about in Ireland in the wake of early postcolonial developments that gave rise to an impressionable and unqualified civil service in a position of power over a nation’s educational development. This is a multifaceted tale of a perfect storm within mathematics development in Ireland whose result was so destructive that its ramifications continue to be felt into the twenty-first century, forty years after a report of a Royal Irish Academy commission of professors of mathematics described the matter as a national scandal. Euclid Transmogrified: A National Scandal may be of interest to mathematics teachers, lecturers in mathematics, mathematical historians, lecturers in education, students of mathematical education, administrators of mathematical education, science administrators, science journalists and those educated in mathematics in Ireland, especially those born between 1954 and 2000. https://sites.google.com/view/euclidtransmogrified1