After 1742 he became ruler over the principality of Anhalt-Zerbst. In 1720 he was appointed Oberlanddrostes of Jever and remained there for the next twenty-two years. During this time, he ordered the building of the Stadtkirche in Jever (which was finally inaugurated in 1736).
In order to administer the principality, he had to return to Zerbst.
John Louis never married and died after only four years of rule.