Eamon de Valera
One of the things that struck me when I watched "Michael Collins" some years back is that the film did not paint a particularly flattering portrait of de Valera. Similarly, he comes across in a mostly negative way in "Rebellion" from the failure to send reinforcements to the vomiting when his sentence was commuted tot the reference to a possible mental breakdown. Granted, if if he had sent reinforcements it likely would have made very little difference.
But for someone who might claim the title Father of his country, he doesn't get a lot of respect in film.