In the war of 1805, in accordance with a treaty of alliance signed at Würzburg on 23 September, Bavarian troops, for the first time since the days of Charles VII, fought side by side with the French, and by the Treaty of Pressburg, signed on 26 December, the Principality of Eichstädt, the Margravate of Burgau, the Lordship of Vorarlberg, the countships of Hohenems and Königsegg-Rothenfels, the lordships of Argen and Tettnang, and the city of Lindau with its territory were to be added to Bavaria. On the other hand, Würzburg, obtained in 1803, was to be ceded by Bavaria to the elector of Salzburg in exchange for Tirol . By the 1st article of the treaty the emperor acknowledged the assumption by the elector of the title of king, as Maximilian I. The price which Maximilian had reluctantly to pay for this accession of dignity was the marriage of his daughter Augusta with Eugène de Beauharnais.