What story does the Spanish epic poema de mio cid tell?

Poema de mio cid is 3,730 lines long and consists of three chapters: exile, marrying a daughter and being humiliated in the oak forest. The epic describes the story that Rodrigo dias was unjustly exiled by the king, but he put national interests first, fought bravely against the Arabs and won, and finally forced the Arab king to surrender to the Spanish king. JaeHee's virtue embodies the qualities of patriotic heroes that people want.