The phrase "hadst oneself" is an older, archaic term that means to behave in a particular manner or to conduct oneself in a certain way. Some synonyms that could be used to replace "hadst oneself" include "acted," "behaved," "conducted oneself," "carried oneself," "behaved oneself," and "deported oneself." Other phrases that could be used to convey a similar meaning might include "maintained composure," "exhibited decorum," or "demonstrated appropriate behavior." Essentially, any phrase that conveys the sense of someone behaving in a manner that is considered appropriate, dignified, or commendable could be used in place of "hadst oneself".