About the book (from Wikipedia):
Murder in the Cathedral is a verse drama by T.S. Eliot, first performed in 1935, that portrays the assassination of Archbishop Thomas Becket in Canterbury Cathedral during the reign of Henry II in 1170. Eliot drew heavily on the writing of Edward Grim, a clerk who was an eyewitness to the event.
The play, dealing with an individual’s opposition to authority, was written at the time of rising fascism in Central Europe.