One reason the regency was never properly wound up, was the Thirty Years' War, which approached Hanau around 1630. When the Imperial troops reached Hanau, Philipp Moritz chose their side, in order to retain the military command of his capital. He was appointed Colonel and was expected to provide three companies. In November 1631, Swedish troops occupied Hanau and King Gustavus Adolphus of Sweden entered the city. Philipp Moritz decided to change sides. He was a Calvinist and for him choosing between the Catholic Emperor and the Lutheran Swedish king may have been like a choice between Scylla and Charybdis. Gustavus Adolphus appointed him to colonel and gave him a Swedish regiment. As a reward for his changing side, he gave him the district of Orb and the shares the Electorate of Mainz had held in the former County of Rieneck and the districts of Partenstein, Lohrhaupten, Bieber and Alzenau. He gave Philipp Moritz's brothers, Heinrich Ludwig (1609–1632) and Jakob Johann (1612–1636) the town and district of Steinheim, which was also a former possession of Mainz. These possessions were lost when the Catholic side gained the upper hand after the Battle of Nördlingen in September 1634. Changing sides again would make Philipp Moritz seem untrustworthy, so he decided to flee. He fled to Metz and from there via Chalon, Rouen and Amsterdam to his Orange-Nassau relatives in the Hague and Delft. He left his youngest brother, Jakob Johann, as regent in Hanau, because Jakob Johann was considered politically neutral.