Hong Kong and Macau locates at the east and the west of the Pearl River Delta respectively, with a close distance of about 64 kilometres in between. Hong Kong and Macau bilateral relations could be traced back to the Middle Neolithic. Both Hong Kong and Macau were under the influence of the same type of Neolithic culture. Tools and ornaments used by both places show tight relationship in idea and trade between the two. Hong Kong became the first European colony in East Asia for being occupied by the Portuguese Empire as Tamão in the early 16th Century. The Portuguese were defeated by the Ming Empire in Hong Kong in 1521, and eventually took Macau as their settlement at the Pearl River Estuary as a replacement. Macau had stood long as the most important European entrepot in East Asia since the 17th Century. Only until Hong Kong fell into the British hands in the early 1840s, Macau faced regional competition from a more opened and free British Colony. Since then, Hong Kong and Macau competed and cooperated for being the commercial centres in the Pearl River Estuary. Eventually Hong Kong developed as one of the busiest entrepots and financial centres while Macau became a world gambling capital.
While tourism is one of the pillars of both economies, Hong Kong and Macau contribute notable proportion of tourists for each other. While Macau is known as the gaming capital of the world and heavily relies on tourism, Hong Kong is the second major source of tourists of Macau. In 2013, 6,766,044 Hongkongers had accounted for near one-fourth of Macau’s total visitor arrivals. On the other hand, while Hong Kong is the world’s most popular tourist destination, Macau is the sixth visitor source market of Hong Kong, just after the Mainland China, Taiwan, United States, and Japan.