There's this: https://en.wikipedia.org/wiki/1918_Irish_general_election
The IRA derived their 'legitimacy' from it.
The IRA derived their 'legitimacy' from it.
And to be quite frank, you are probably thinking of the Provisional IRA when you put legitimacy in quotes, where as this was the original IRA, who basically have nothing in common with the Provos (as they were called when I were a lad) except the name.