What are three causes of the Great Schism in Christianity?

I don't know what the other two were but one is that people were confused of who is head of the church which was Jesus.

1) Michael Cerularius' disagreement with the Catholic practice of not allowing clergy members to marry.

2) Latin Church addition of the term 'filioque' to the Nicene creed.

3) Cerularius excommunicated bishops of Constantinople for using the term.