the niederlahngau was held by the conradines until the second half of the 10th century. the last mention of a conradine count was in 966. the niederlahngau went over to the countship of diez. the extensive conradine allodial lands in the niederlahngau came, probably through familial relationships, to the counts of (alt-) leiningen. after the extinction of this house in 1220, it was distributed among the related dynasties of nassau, runkel/westerburg, isenburg/limburg, and virneburg.