What do historians mean when they refer to the historical context of an event

The circumstances surrounding an event.

Explanation:

When historians refer to the historical context of an event, they are talking about the political, cultural, social and economic environment that existed in that particular moment in time. All of these characteristics can affect the ways in which we interpret history. If we do not take these into account, we could end up misunderstanding or misinterpreting the historical events we are studying.