As emperor, Charles began the construction of a palace at Sélestat in Alsace. He modelled it after the Palace at Aachen which was built by Charlemagne, whom he consciously sought to emulate, as indicated by the "Gesta Karoli Magni" of Notker the Stammerer. As Aachen was located in the kingdom of his brother, it was necessary for Charles to build a new palace for his court in his own power base of western Alemannia. Sélestat was also more centrally located than Aachen.