for a spring offensive. He summoned the Comes Italiae Sebastianus, with the Italian and Illyrian legions, to join Jovinus and Severus, the magister peditum. In the spring of 368 Valentinian, his eight-year-old son Gratian and the army crossed the Rhine and Main rivers into Alamannic territory. They did not encounter any resistance initially – burning any dwellings or food stores they found along the way. Finally, Valentinian fought the Alamanni in the Battle of Solicinium; the Romans were victorious but suffered heavy casualties. A temporary peace was reached and Valentinian returned to Trier for the winter. During 369, Valentinian ordered new defensive works to be constructed and old structures refurbished along the length of the Rhine's west bank. Boldly, he ordered the construction of a fortress across the Rhine in the mountains near modern Heidelberg. The Alamanni sent envoys to protest, but they were dismissed. The Alamanni attacked the fortress while it was still under construction and destroyed it. In 370 the Saxons renewed their attacks on northern Gaul. Nannienus, the comes in charge of the troops in northern Gaul, urged Severus to come to his aid. After several modest successes, a truce was called and the Saxons handed over to the Romans young men fit for duty in the Roman military – in exchange for free passage back to their homeland. The Romans ambushed them and destroyed the entire invading force. Valentinian meanwhile tried to persuade the Burgundians – bitter enemies of the Alamanni – to attack Macrian, a powerful Alamannic chieftain. If the Alamanni tried to flee, Valentinian would be waiting for them with his army. Negotiations with the Burgundians broke down when Valentinian, in his usual high-handed manner, refused to meet with the Burgundian envoys and personally assure them of Roman support. Nevertheless, rumors of a Roman alliance with the Burgundians did have the effect of scattering the Alamanni through fear of an imminent attack from their enemies. This event allowed the magister equitum Theodosius to attack the Alamanni through Raetia – taking many Alamannic prisoners. These captured Alamanni were settled in the Po river valley in Italy, where they were still settled at the time Ammianus wrote his history. Valentinian campaigned unsuccessfully for four more years to defeat Macrian who in 372 barely escaped capture by Theodosius. Meanwhile, Valentinian continued to recruit heavily from Alamanni friendly to Rome. He sent the Alamannic king Fraomarius, as a