Hesse has no unified history. Enfeoffed first to the dukes of Franconia, later to the counts of Thuringia, Hesse emerged in 1247 as a landgraviate immediately subject to the emperor under a branch of the house of Brabant. Landgrave Philip the Magnanimous (see Philip of Hesse), a leading figure in the German Reformation, was responsible for reuniting a territory that had been torn by border disputes with neighboring areas. At his death (1567) Philip's lands were divided among his four sons, with Kassel, Marburg, Rheinfels, and Darmstadt their respective capitals. Upon the demise shortly afterward of the Rheinfels (1583) and Marburg (1648) lines, the whole territory was held by the two remaining lines—Hesse-Kassel and Hesse-Darmstadt. The Congress of Vienna (1814–15) awarded Hesse-Kassel and Hesse-Darmstadt substantial territorial gains. Electoral Hesse, the free city of Frankfurt, and Nassau, having all three sided with Austria in the Austro-Prussian War (1866), were annexed by Prussia and were merged (1868) in the province of Hesse-Nassau, of which Kassel became the capital. The former state of Waldeck was incorporated into Hesse-Nassau in 1929. The grand duchy of Hesse-Darmstadt also had sided against Prussia. It ceded Hesse-Homburg (which it had just acquired through the extinction of that line). In 1871, Hesse-Darmstadt joined the newly founded German Empire, and it continued under its own dynasty until the German revolution of 1918. The Battenberg (Mountbatten) family is a morganatic branch of the house of Hesse. In World War II nearly all the major cities of Hesse suffered severe damage.