for example, the lahngau may originally have belonged not to the conradines but to the robertian sphere of influence. through an exchange at the beginning of the 9th century, the conradines may have taken over the robertines’ possessions in east francia and the robertians received the conradine possessions on the loire river in west francia. such a process would explain the equation of udo of the oberlahngau with odo i of blois, as well as the extensive holdings in the lahngau by lorsch abbey (founded by the robertians).