Hello. I am writing a novel, and one of the main events is that where a kingdom is invaded by another (an empire, to be precise), at first due to greed then it is revealed for other reasons which are not important for me to point out. So far, the prince of the kingdom managed to escape, not without having his home destroyed and ravished, but then he is to gather allies and then retake his kingdom, rebuilding it, etc. My question is, is there any records in history where something like this happened? It doesn't have to be exactly the same, it can be a prince, general of the first country or whatever. I simply want a reference of the first idea: a country which is invaded, but is later able to rise again with the help of allies, and which manages to expel the invaders for good.