Lake Constance, Iller and Danube lines again. Here, from the late 3rd century, the emperors Diocletian and Maximian built the chain of forts of the so-called Danube-Iller-Rhine Limes. Nevertheless, the Alemanni repeatedly invaded the territory of the Empire, since they often exploited the internal power struggles of the Romans which were usually associated with an almost complete withdrawal of the Limes troops. In 357 the Battle of Argentoratum took place near what is now Strassburg, in which Emperor Julian the Apostate succeeded in routing the Alemanni and taking their King Chnodomar prisoner. In 378, allegedly 40,000 Alemannic Lentienses broke through the Rhine Limes—either directly at the Sponeck crossing or near Breisach—devastating the border areas and penetrating into the interior of Gaul. To defend his own territory the Western Emperor, Gratian, had to recall a large part of his army from Illyricum, whence it had been dispatched to assist his uncle, the Eastern Emperor, Valens against the Goths and Alans invading Thrace. The invading Alemanni were soon thrown back across the Rhine by Gratian and his Frankish military leaders, the comes Nannienus and the comes domesticorum Mallobaudes after the nearby Battle of Argentovaria, but this victory cost Valens dearly, since Gratian then arrived too late in the Balkans, to save Valens from the catastrophic defeat at the Battle of Adrianople. In August 369 Emperor Valentinian I was staying in the neighboring fort Mons Brisiacum, from where he could, at least temporarily, coordinate and monitor the large-scale construction activities of the Romans on the Rhine Limes. In the course of this, the fortress in Argentovaria was built. Judging by the number of coins, it existed until the withdrawal of the regular border troops under Stilicho between 401 and 406, and possibly even until the middle of the 5th century. The ruins of the fort were probably still visible above ground until the end of the 17th century. From 1701 on it was removed to extract stone material for the construction of the Neuf-Brisach fortress. Fort A Roman military base had existed in Biesheim since the 1st century AD. Altogether, two Julio-Claudian wood and earth forts were found for this period, but they were abandoned in the late 1st century. Hans Ulrich Nuber suspects another predecessor from the time of Augustus under the late antique fort. Oedenburg-Altkirch represents a new type of fort within the comprehensive late antique fortress construction program. The Valentinian