After the defeat of Brennus, Bathanatius led his people to the banks of the Danube, at the confluence of the Sava, roughly around Belgrade, where they settled down. The way by which they returned received from their leader the name of Bathanatia; and his descendants were called Bathanati.
References
↑The Ancient Celts by Barry Cunliffe, ISBN0-14-025422-6, 2000, page 86: "... distinguished suggests that one of the returning groups, led by Bathanatos, finally settled in the Middle Danube region at the confluence ..."
↑Celts - a History, The by Daithi O HOgain, ISBN1-905172-20-6, 2006, page 60: "... those who, on their return from Greece under their leader Bathanatos, had settled at the confluence of the Danube and the ..."