Remembering the treatment that had been accorded the Knights and soldiers of St. Elmo, the Maltese inhabitants of Senglea took no prisoners. Hence there arose the expression (used in Malta to this day) 'St. Elmo's pay' for any action in which no mercy is given.
Ernle Dusgate Selby Bradford, The Great Siege
mercy, retribution, revenge, st-elmo, war