During the War of the Fifth Coalition, Austrian troops occupied Regensburg on 20 April 1809; it was shelled and stormed by French troops three days later. In the Treaty of Paris, Dalberg conceded Regensburg to the Kingdom of Bavaria, which formally incorporated the city on 22 May 1810. In return for conceding Regensburg, Dalberg was granted Hanau and Fulda, which he combined with the Principality of Aschaffenburg to create the Grand Duchy of Frankfurt. Although he had lost the Principality of Regensburg, Dalberg retained the title of Archbishop of Regensburg until his death in 1817, after which time the archbishopric was downgraded to a suffragan diocese of Munich and Freising.