Lothair was given to understand that Louis and Charles were supporting each other with considerable armies.[197] Seeing that his plans were crushed in every direction, he made a long but profitless expedition and abandoned the country about Tours. At length he returned into France,[198] worn out with fatigue, as was also his army. Pepin,[199] bitterly repenting that he had been on Lothair's side, withdrew into Aquitaine. Charles, learning that Otger, bishop of Mainz, objected to the proposed passage of Louis by way of Mainz to join his brother, set out by way of the city of Toul[200] and entered Alsace at Saverne. When Otger heard of this, he and his supporters abandoned the river and sought places where they might hide themselves as speedily as possible. On the fifteenth of February Louis and Charles came together in the city formerly called Argentoratum, now known as Strassburg, and there they took the mutual oaths which are given herewith, Louis in the _lingua romana_ and Charles in the _lingua teudisca_. Before the exchange of oaths they addressed the assembled people, each in his own language, and Louis, being the elder, thus began: [Sidenote: The speech of Louis the German] "How often, since the death of our father, Lothair has pursued my brother and myself and tried to destroy us, is known to you all. So, then, when neither brotherly love, nor Christian feeling, nor any reason whatever could bring about a peace between us upon fair conditions, we were at last compelled to bring the matter before God, determined to abide by whatever issue He might decree. And we, as you know, came off victorious;[201] our brother was beaten, and with his followers got away, each as best he could. Then we, moved by brotherly love and having compassion on our Christian people, were not willing to pursue and destroy them; but, still, as before, we begged that justice might be done to each. He, however, after all this, not content with the judgment of God, has not ceased to pursue me and my brother with hostile purpose, and to harass our peoples with fire, plunder, and murder. Wherefore we have been compelled to hold this meeting, and, since we feared that you might doubt whether our faith was fixed and our alliance secure, we have determined to make our oaths thereto in your presence. And we do this, not from any unfair greed, but in order that, if God, with your help, shall grant us peace, we may the better provide for the common welfare. But if, which God forbid, I shall dare to violate the oath which I shall swear to my brother, then I absolve each one of you from your allegiance and from the oath which you have sworn to me." After Charles had made the same speech in the _lingua romana_, Louis, as the elder of the two, swore first to be faithful to his alliance: [Sidenote: The oath of Louis]