Wiktionary
commissionership
n. The role or office of commissioner.
Usage examples of "commissionership".
This world, namely Earth in System 5417, is under the Commissionership of the High Hiscount Chaverlem Par-Chavorlem, against whom Wattol Forlie does bring the following grave charges.
He could expect a subsequent commissionership on a prime human-colonized planet like Hermes, where plenty of glamour was available.
He is, as you say, very much your friend and he did throw out some confused remarks about the possibility of a commissionership or even some civilian employment, conceivably to do with hydrography.