An overseer's job was to ensure that the slaves were doing as much work as they should be and that everything was being done to improve the crop yield. Overseers were generally hired seasonally and a planter would generally try and find a new one for the next season.
In "Romeo and Juliet" after an enraged Romeo slays Tybalt in an act of revenge for the death of his dear friend Mercutio, he is banished from Verona by the Prince who declares,