The movie opens with the off-camera murder of a young man by British soldiers, and the violence continues from there. This isn't, however, violence for the sake of being violent. It's an integral part of the storyline and portrays a very real part of life during the Irish War of Independence. Because of its historical context, it's really up to the parent to decide if this movie is suitable for their child. I would, however, reserve it for older kids.
I watched this movie with my husband and son - 12. We were all deeply moved and a year later my son is still talking about it. He loves history and because our family comes from Ireland he was very interested. This movie is graphic and intense, but it isn't violence for entertainment, it is part of the story and necessary - that makes all the difference in my opinion.