hence:
adv. 因此今後
Hence, this mother chose to leave the village.
這位母親因此選擇了離開村莊。
henceforth:
adv. 從此以後
Henceforth, you are my legal wife, and I will make you happy.
從今往後,你就是我合法的妻子了,我會讓你幸福的。Henceforth, I hope you won't make such mistakes as you did today.
我希望從現在開始你不要再犯今天這樣的錯誤了。