Facebook founder Mark Zuckerberg features in a long line of university dropouts who became millionaires after founding technology companies - Bill Gates and Steve Jobs among them.

But 12 years after leaving Harvard to work on Facebook full time, he has returned to pick up his degree.

Zuckerberg founded what was then called "The Facebook" in his college dormitory in 2004. The service was at first limited only to Harvard students before expanding to other Ivy League universities.

He is due to deliver the university's commencement address, a speech given to graduating students, later on Thursday. After receiving the honour he posted a photo of him with his parents Edward and Karen Zuckerberg.

Zuckerberg returned to the room where he built Facebook along with his co-founders, Dustin Moskovitz, Eduardo Saverin, Andrew McCollum and Chris Hughes.

On Wednesday, he said his upcoming speech would "share what I've learned about our generation and the world we're all building together".

Even after the company moved its headquarters to California, Zuckerberg continued to be enrolled at Harvard until he dropped out in November 2005. "I'm not coming back" he told the university paper The Crimson.

His honorary degree comes 12 years later, a little quicker than it took Bill Gates, another famous Harvard dropout to get his. Gates, who left to found Microsoft in 1975, did not receive his honorary degree until 2007.

Last week, Zuckerberg shared a video of him finding out he had been accepted into Harvard.