。
The people stood up against the tyranny.
Literal
People [topic-は] tyranny/oppression [against-に] stood-up-and-faced.
立ち向かう is a compound verb: 立つ ('stand') + 向かう ('face toward'), meaning 'to stand up to' or 'to confront.' Compound verbs of this shape are common and often carry nuance that neither component alone captures — here, courageous defiance rather than mere opposition.