I am doing a report on why this man was a legend, and what made him become a legend. I also need some information on his life.
I decided since this was a BIG report, that i should post here and see what other people think about him. Any ideas on what i could include in my report?

Just some quick information about him that I already have:

El Cid, who is commonly known as Rodrigo (or Ruy) Diáz de Vivar, was a commander under King Alfonso VI of Castile in the eleventh century. Tradition and Legend both cast a shadow over this man, and his existence is still questioned. He fought battles against himself in a certain way, but always came out victorious for himself.
When saying, “He fought battles against himself in a certain way”, he really did. He fought for Alfonso against the Moors, and he fought for the Moors against Alfonso. In the end, he did himself a great favor by eventually conquering the kingdom of Valencia for himself.

I wrote this as the first two paragraphs, and that is all i have so far.