Would you correct my article?

This task is from a past CAE exam. Could you kindly correct any mistakes in the text and give an opinion about it? Is it a kind of answer that is appropriate in such an exam?

Attachment 1444

The myth of Lech Walesa
Poland, which is a country that I come from, does not happen to be mentioned in the frontlines of the newspapers or in the news on television very often. We are rather not in the centre of the world’s attention. There are not too many persons of polish nationality who achieved worldwide recognition either. However, there are two personalities who managed to do otherwise. They are the deceased John Paul II and former polish president Lech Walesa. In my article I will present the latter.
Lech Walesa achieved wide popularity being the leader of a massive anti-government, working class movement in the communist period. He was established as an icon of defiance against totalitarian socialist regime, frequently portrayed as warrior fighting for social justice, and above of all, someone who vastly contributed to the collapse of the communist system in the eastern Europe To this day, he is considered by many to be a man of great courage and a very important figure of the 20^th century.
However, this established and commonly acknowledged image doesn’t actually reflect the truth. The reality is that the mighty Union leader was in fact a collaborator of the communist secret service. What is more, in the early period of fresh polish democracy, he allowed his supposed enemies to remain in the political system. Not to mention his conceit and terrible manners.
What is striking is that he is still considered in every corner of the world to be someone of a hero, and people simply do not realize that this is just a myth. A kind of ideal, a false image created by the media. The question is, will it ever change? Will the truth ever manage to emerge and see the light?