Isenburg was a region of Germany which eventually located itself in southern Hesse, located in territories north and south of Frankfurt. The states of Isenburg emerged from the Niederlahngau (located in the Rhineland-Palatinate), which partitioned in 1137 into Isenburg-Isenburg and Isenburg-Limburg-Covern. These Counties partitioned between themselves many times over the next 700 years. It was not until 1806 that there was a state called simply "Isenburg". When the Holy Roman Empire was defeated by Napoleon Bonaparte of France in that year, the empire was abolished and the Confederation of the Rhine was established amongst the various German states. As an incentive to join the Confederation, it was stated that any state which joined could mediatise their neighbours. Prince Charles of Isenburg-Birstein joined the Confederation and was granted the mediatised Isenburgian Counts (Isenburg-Büdingen, Isenburg-Meerholz, Isenburg-Philippseich, and Isenburg-