The Siege of Donegal took place in 1601 during Tyrone's Rebellion when a force led by Hugh Roe O'Donnell laid siege to the settlement of Donegal. The garrison of the town were a mixture of Irish Army troops and Gaelic forces loyal to the Crown led by Niall Garve O'Donnell. Heavy fighting took place during the month-long siege in which Donegal Abbey was wrecked by an accidental gunpower explosion.