 According to this annal, he had been granted a stewardship by Cenn Fáelad, but was unsatisfied with this and encouraged by his friend of Fir Rois he challenged Cenn Faelad to battle and won the kingship.He appears to have faced resistance from the King of Leinster, a Battle of Loch Gabor(Lagore) was fought in 677.There was mutual slaughter on both sides but Finsnechta emerged the victor.