Obama's Father History?

In his autobiographical book "Dreams from My Father," Barack Obama tells the history of his father and paints a heroic picture of him as having emerged from a poor Kenyan village, where he was nothing more than a simple goat herder, to become a Harvard-educated economist, destined to return to Africa to fulfill his promise.
But now people say that is not the truth and that his father had some serious drinking problems and that he was a polygamist who had already abandoned one wife and child in Africa when he met Obama's mother in Hawaii.
What's the truth? What's the real history of Obama's father?

The real history of Obama's father is a little confusing. The president says he was a good man but his half brother now has broken his media silence to discuss his new novel — the semi-autobiographical story of an abusive parent patterned on their late father, the mostly absent figure Obama wrote about in his own memoir.

In the book Obama's brother wrote:

"My father beat my mother and my father beat me, and you don't do that, it's something which I think affected me for a long time, and it's something that I've just recently come to terms with."

President Obama's parents separated two years after he was born in Hawaii in 1961. The senior Obama, a Kenyan exchange student, divorced the president's mother, Stanley Ann Dunham, in 1964 and had at least six other children in his native Kenya.