The War in Mide was the last War of Irish Unification.
After the Twelve Days War had ended, the Duchy of Leinster was the largest and most powerful state in Ireland. However, the War of Welsh Aggression had diverted the attention of Murchaid Ui Mordha. During this time, the Duchy of Connacht had conquered Tir Connail, in the War of Connacht. Mide was now the only neutral territory in Ireland, and Murchaid needed to invade it to achieve his goal of complete domination of Ireland and eventual unification.
Murchaid's armies initially attempted a sneak attack similar to the invasion of Tir Eoghain in the Twelve Days war. However, Mide's Spymaster realized the presence of the soldiers and raised the guard. The Battle of Mide then began. Mide's army was defeated, although it took nearly two months to hunt down and destroy the last few regiments. Instead of wait for a siege like the rulers of Ulster and Tir Eoghain, the Count of Mide fled his capital and moved from town to town, encouraging guerrilla warfare and keeping just ahead of Murchaid's forces. Eventually, the Count was caught and killed and the pockets of resistance faded, but it had taken nearly eight months, and the strain of maintaining the army had near bankrupted the Duchy of Leinster.