|Stages in the development of the ports of Rotterdam and Antwerp|In: Geoforum. Elsevier: Oxford. ISSN 0016-7185, more
Rotterdam and Antwerp, situated in close proximity to each other, have evolved over the past seven centuries to become the world's largest and Europe's second largest ports respectively. Mainly for political reasons, the stages of rise and decline occurred in complementary time periods, until freedom of inland shipping became international law on the Rhine and in the Rhine-Maas-Schelde delta region in the 19th century. Since then Antwerp's ascendancy has occurred without serious interruption, though areal expansion is now limited by the Belgian-Dutch boundary. Rotterdam, on the other hand, has faced two difficult periods involving ease and speed of access to the North Sea, and destruction during World War II.