(“Batavis” and Boiodunum) Bavaria, Germany.
At the confluence of the Inn (Aenus)
and the Danube. The Inn marked the boundary between
the provinces Raetia and Noricum, and therefore the
double military occupation of the river's mouth within
Passau was necessary. On the small ridge between the
Danube and the Inn a Late Celtic settlement (oppidum
Boiodurum?) is supposed to have existed. One can assume after ca. A.D. 150 the existence of an auxiliary castellum on the Raetian side for the Cohors IX Batavorum (Batavis). The location is not known, but in Late
Roman times the hill of the old town was fortified,
probably on the site of Batavis, which is mentioned several times in Eugippius' Vita St. Severini
. On the Noncum side a small castellum was built as early as the reign of Domitian (probably Boiodurum). Whether the
castellum was destroyed in the 3d c. is not certain. A
settlement in the 4th c. has been documented. The place
is perhaps identical with the military field in the late 4th
c. A.D. mentioned in the Notitia Dignitatum
The location of the Raetian castellum Batavis is not
known. It is unlikely to have been on the hill of the old
town. However, traces of a Roman vicus (?), which was
fortified in Late Roman times, have been found there.
The castellum Boiodurum (ca. 142 x 90 m) in Noricum
on the right bank of the Inn side has been partially
The Oberhausmuseum Passau contains numerous
Roman finds from Batavis and Boiodurum.
P. Reinecke, Zur Frühgeschichte von
(n.d.); id., “Grabungen auf dem Altstadthügel,”
Passau: Kleine Schriften z. Vor- und frühgeschichtlichen
(1962) 124ff, 131ff; H. Schönberger, “Das
Römerkastell Boiodurum-Beiderwies zu Passau-Innstadt,”
. 15 (1956) 42ff; J. Pätzold, “Zur Topographie von Passau,” Führer z. vor- u. frühgeschichtlichen Denkmälern 6 (1967) 7ff.