The principle of the common heritage of mankind was introduced in international law to internationalize certain common spaces beyond national jurisdiction. It has found a certain application in outer space as well as in the Antarctic, but it is with respect to the oceans that it has so far found its fullest exposition. Since the principle is very much tied to the Area in the United Nations Convention on the Law of the Sea, i.e., the seabed and ocean floor and subsoil thereof beyond the limits of national jurisdiction, it can be said to have triggered that convention, but at the same time was also almost responsible for its demise. As a consequence, its content has changed over the years. The present article intends to have a closer look at how this principle at present relates to the obligation of broad-margin states to establish the outer limit of their continental shelf.