Grace O'Malley, known in Gaelic as Grainne Ni Mhaille, is one of the most famous characters of Irish history. Her clan, the O'Malleys, lived in western Ireland, in a region where many of the clans supplemented their fishing and trading income through piracy. The O'Malley clan was no exception, and Grace O'Malley became a pirate queen, the commander of a large armada of seaborn raiders.

Grace is often described as a clan chieftain, but she never held such a position. The force she commanded included the warriors of several different clans, including not only O'Malleys but Burkes and others. These men didn't follow her because of clan-based loyalties- under the native Irish Brehon law-code, a woman could not officially be a clan chief. Rather, they followed her solely due to their personal loyalty to Grace herself, and their confidence in her abilities as a military, political and piratical leader.

Like most of the clan chiefs, though, she had no larger national vision or sense of patriotism. She fought to protect her own position and that of her followers and immediate relatives, not to protect Gaelic Ireland as such. When her position would be helped by allying with the English, she allied with the English. When English commanders tried to threaten her position, she rebelled against the English. In this, she was no different from the chiefs of major clans such as the O'Neills or the O'Donnells. When she ended up fighting on the English side at the Battle of Kinsale, it was solely to solidify her local position.