The borders of the Middle East were drawn during World War I by a Briton, Mark Sykes, and a Frenchman, Francois Picot.
The two diplomats' pencils divided the map of one of the most volatile regions in the world into states that cut through ethnic and religious communities.
Later dubbed the Sykes-Picot treaty, the secret agreement was signed by Paris and London on May 16, 1916, to become the basis on which the Levant region was shaped for years to come.
A century on, the Middle East continues to bear the consequences of the treaty, and many Arabs across the region continue to blame the subsequent violence in the Middle East, from the occupation of Palestine to the rise of the Islamic State of Iraq and the Levant (ISIL), on the Sykes-Picot treaty.
In this interactive piece, complied in collaboration with Al Jazeera English Online, we revisit the circumstances that led to the signing of this critical agreement and the events that unfolded afterwards.