Isenburg is a region of Germany located in southern present-day Hesse, located in territories north and south of Frankfurt.

The states of Isenburg had emerged from the Niederlahngau (located in the Rhineland-Palatinate), which had partitioned in 1137 into Isenburg-Isenburg and Isenburg-Limburg-Covern.

These countships had been partitioned between themselves many times over the next seven hundred years.