At Mons Lactarius in 553, Narses destroyed the last Ostrogothic army and Teias was killed, ending the kingdom.
Mons Lactarius was fought in 553 on the slopes near Vesuvius, and it is where the Ostrogothic kingdom ended.
The Goths under Teias had withdrawn south after Taginae and were cut off from supply on the mountain, and the battle was fought by an army that had nothing left to do but fight.
It lasted two days, Teias was killed on the first, and the survivors negotiated their way out of Italy rather than being destroyed.
After Totila's death the surviving Goths elected Teias and moved into Campania, both to secure the royal treasure at Cumae and to link up with a promised Frankish intervention that never came.
Narses followed and manoeuvred them onto the high ground, then blocked their supply route.
Starvation rather than assault decided the position: the Goths could stay and starve or come down and fight.
They came down, and the fighting was infantry work on broken slopes with no room for manoeuvre — the Goths on foot, having lost or eaten their horses.
Procopius gives Teias a set-piece death: fighting in the front rank, holding his shield until it was so heavy with embedded spears that he called for a fresh one, and being struck down in the moment of the exchange.
The Goths fought on through a second day after he was killed, then sent to Narses for terms.
The terms were unusually generous. The surviving Goths were permitted to leave Italy with their movable property, on the undertaking that they would never again make war on the empire.
Narses accepted rather than pressing for annihilation, which was pragmatic: he still faced Frankish and Alemannic invasions and Gothic garrisons holding out in the north.
The Ostrogothic kingdom, founded by Theodoric sixty years earlier, ceased to exist.
It is the end of Gothic Italy, and with it the end of the most successful of the post-Roman successor states.
It also completes the reconquest — and completes the demonstration of what the reconquest cost. Italy was depopulated and impoverished, and within fifteen years the Lombards took much of it with little resistance.
Procopius closes his account of the war here, and the literary care he gives Teias's death is a measure of what he thought had ended.