Facebook founder Mark Zuckerberg, one of Harvard’s most famous dropouts, this week returned to the Ivy League school to pick up his degree – albeit only an honorary one – 12 years after quitting.

Mr Zuckerberg, one of the richest people in the world, also gave a commencement address to this year’s graduating class, praising students for accomplishing “something I never could”.

“If I get through this speech, it’ll be the first time I actually finish something at Harvard,” he said.

Mr Zuckerberg launched Facebook from his dormitory room in 2004. The social network was initially limited to Harvard students only. It later expanded to other Ivy League universities, before being rolled out globally.

Earlier this week, Forbes magazine named Facebook the world’s fourth most valuable brand. Mr Zuckerberg is the world’s fifth-richest person, with an approximate fortune of $64.2bn, according to the Bloomberg Billionaires Index.

In 2010, Time magazine named Mr Zuckerberg Person of the Year and Vanity Fair magazine listed him among its “top 100 most influential people of the information age”.

Like other tech entrepreneurs before him, Mr Zuckerberg has also become known as a philanthropist, pledging to direct tens of billions of dollars to a range of causes. He was studying computer science at Harvard before he moved to Palo Alto, in California, to run Facebook.

Bill Gates, currently the world’s richest human, dropped out of Harvard in 1975, which was the same year he co-founded Microsoft. Mr Gates received his own honorary degree from Harvard back in 2007.