What is "sileraioi"

The Sileraioi were a group of ancient mercenaries most likely employed by the tyrant Dionysius I of Syracuse, though it is unknown at what time during Dionysus' reign and to what capacity the Sileraioi were employed. They began to issue coinage between the years 357 and 336 BC, and this coinage provides the bulk of evidence we have of their existence, since no ancient authors wrote about them by name and the location of any "city" of the Sileraioi has not been conclusively determined. However, much can be inferred about the ruthless character of the Sileraioi based on what ancient authors wrote about Dionysus' mercenaries in general.