the lead on the playing field, when it came to religion, there was no question, osama was in charge. that s the mosque we used to pray in, yes, yes. reporter: five times every day, devout muslims turn towards the holy city of mecca, to pray. osama was always among them. for him, it was a must. reporter: it is something of a mystery, why this son of a wealthy family was drawn to such rigid, religious beliefs. over time, batarfi saw his best friend become even more of a fundamentalist, striving to live according to his ultrastrict interpretation of the holy koran. no pictures, no music, and after that, not even tv. unless there s news. reporter: osama s religious
devotion went beyond living a simple pious life. he had begun to believe it was his duty to prepare to one day fight for and defend islam. osama s training ground, the desolate saudi desert. the son of a multimillionaire was now preparing for a life without luxuries or even basic essentials, a life as a holy warrior. i heard from his brothers when they go there, they sleep on the sand. there s no blanket if it s cold, and they, you know like soldiers. reporter: batarfi had no desire to join osama s army, so the two friends began to drift apart. i would prefer the beach. i was more romantic. you know, i was thinking of
rose from a menial laborer to head one of the largest and most successful construction companies in the middle east. he built the airport. he built virtually everything that was standing more than two meters high had been built by bin laden. reporter: he had more than 50 children. osama was born in 1957 here in this riyadh neighborhood. he was the only child his mother had with muhammad bin laden before they divorced. then bin laden and his mother moved to jeddah and lived here apart from the other wives and children. muhammad bin laden died when osama was just 10 years old. the school was abuzz with the news that mohammed bin laden had been killed in a plane crash. reporter: with so many siblings, it s hard to say how close osama was to his father or how the loss affected him. this photograph from the early
we would watch cowboys movies and karate movies, things that, you know, action movies. reporter: batarfi took us to the field where he and bin laden played soccer as teenagers. and just looking at it brings a lot of memories. i enjoyed being a captain, really, and telling people what to do. reporter: on the soccer field batarfi was the leader. osama, the follower. but i would tell him what to do, and he was a good soldier. he would follow orders. usually because he was taller than most of us and older, he would play in the front, because this way, he could use his head to, you know, score. reporter: batarfi says the teenage osama would usually take the high road. he remembers a time his friend was being bullied. so i went running to the guy, and i pushed him away from osama and solved the problem this way,
osama sat about two-thirds of the way back on the right, by the windows. he was not an outstanding student academically. on the other hand, he was a very bright boy. reporter: although arabic and religious instruction took priority, the al fatah school, one of the top schools in the kingdom, was surprisingly progressive. the boys had a western uniform. they had trousers, shirts, jackets and shoes. reporter: faifel shaler had taught a number of bin laden s brothers. osama s family was well-known in saudi arabia. his father s career was the stuff of legend. the bin ladens were almost a storybook success. reporter: in saudi arabia, the bin laden name is everywhere. it s a vast empire with humble beginnings. the family patriarch, mohammed, seen here in rare photographs,