A first Count Henry at Hoya in Saxony appeared as a vassal of Archbishop Hartwig II of Bremen in 1202.

He had disputes with the local Hodenberg noble family at Hodenhagen Castle over their estates on the Weser which were gradually acquired by Count Henry and his descendants until 1313.

The acquisition of Nienburg led to a long-term conflict with the Bishops of Minden who baulked at the expansionism of their comital neighbours.

In 1345 the brothers Gerhard III and John II of Hoya, divided the county among themselves.

When the elder branch of the Gerhard line at Hoya became extinct in 1497, the territories were re-unified under John's descendant Count Jobst I residing at Nienburg.