To make one on the opposing side of an issue suffer for their position, only for that suffering to cause other people to sympathize with the victim, thus strengthening their cause. The British government's biggest mistake in dealing with the Irish revolutionaries was to execute the leaders of the 1916 uprising. By making martyrs of them, the government unified the Irish people in a position of revolt.

To go out of one's way to do difficult or unpleasant things, especially to engender pity or sympathy in others. My mother always made a martyr of herself at Christmas time, slaving away in the kitchen and then complaining about how tired she was.