Hugh O'Donnell was a prominent Irish leader in the late 16th century, known for his role in the Nine Years' War against English rule in Ireland. Born into the O'Donnell clan, he became the 2nd Earl of Tyrconnell and was a key figure in the struggle for Irish independence. His leadership was marked by alliances with other Gaelic lords and efforts to unite Irish forces against the English crown. O'Donnell's most notable achievement was his victory at the Battle of Clontibret in 1595, which bolstered his reputation. However, after a series of conflicts, he eventually fled to Spain in 1607, an event known as the Flight of the Earls. His legacy remains significant in Irish history as a symbol of resistance against colonialism.