 The fighting was focused on Munster; Máel Sechnaill sought to increase his influence over the kings there.He took hostages from the province in 854, 856 and 858, and the power of the over-kings had been weakened in 856 by a Viking raid on the royal centre at Lough Cend, when Gormán son of Lonán, a relative of Munster's over-king, was killed alongside a great many others.This weakness likely drew the gaze of both Máel Sechnaill and the Vikings, and their competition for Munster's resources may have been the cause of the war.