Here's how Li Ka-shing became the richest man in Hong Kong

Hong Kong billionaire Li Ka-shing may no longer be the richest man in Asia, but with a current estimated net worth at $20.1 billion, his wealth is still nothing to sneeze at.

Li Ka-shing has an incredible rags-to-riches story. He was forced to drop out of school as a child to support his family, but today, he is one of the world's richest men. He opened his first factory at the age of 22 and within a few years saw great success as a manufacturer, property developer, business magnate, and investor.

He's now become a major investor in disruptive technology. He was one of the first big investors in Facebook, and his most recent big acquisition was the British telecom company, O2, which he purchased at the end of March for $15 billion.