It is the largest free standing sculpture ever carved from a single block; an icon recognised around the globe. The Sphinx, a lion with the face of a mighty pharaoh, towers twenty metres high and stretches seventy metres long.

It is a silent witness to thousands of years of history. For over 4,500 years it has stood guard in front of the Giza Pyramids, yet it remains one of history's most enigmatic mysteries. Based in Cairo, top Egyptologist Dr Vassil Dobrev has spent over twenty years researching the Sphinx, and has a theory that proposes a completely new and previously unrecognised pharaoh as the builder of the Sphinx.

His name was Djedefre, and according to Dobrev's pioneering research, he was the true driving force behind some of the most remarkable structures in all of ancient Egypt. Yet to prove that this little-known king created this incredible monument, Dobrev must first crack a conundrum that has baffled Egyptologists for years - he must unmask the Sphinx to reveal the identity of its face. Yet the final proof lies in the intricacies of the design - does the Sphinx bear the face of the Djedefre's father, Khufu? To solve the mystery Dobrev forced his mind back 4,500 years to the time of the ancient Egyptians.