On this day the Macau Peninsula, Taipa, Coloane along with the islands Lapa, Dom João and Montanha were handed over (strictly speaking, back) to China. The territory had been administered by Portugal from the mid-16th century until late 1999, when it was the last remaining European colony in Asia.
The Portuguese presence dated back to the end of the 17th century when a group of missionaries established themselves on these Chinese islands. Following the Japanese invasion of China in 1938, the Portuguese had officially occupied these three lightly populated islands in order to create a larger more economically viable Macau (the colony had previously consisted of Macau Peninsula itself and the islands of Taipa and Coloane). Because of their alliance status as an Axis Power , Japan respected Portuguese sovereignty. However, as the Greater Asian Prosperity Sphere began to flourish, Japan had grown to see the wisdom of working with them to diminish the influence of Hong Kong and Singapore as regional entrepôts.
As Great Britain and her Far Eastern Empire waned, China rose again as a civilization that had endured for millennia and was certain to out-live the few centuries of European belligerence. After Allied occupation, Portugal maintained its colonies, struggling against post-colonization with assistance from France. Eventually its influence diminished, and under the Sino-Portuguese Joint Declaration, Macau was classified as "a Chinese territory under (temporary) Portuguese administration" taking a slow transition into full sovereignty. This was in reality merely a "smoke and mirrors" deal simply to avoid capital flight. On the eve of the twenty-first century, China quietly closed the door on the wreckage of the previous four hundred years. For Western Capitalists, it was the end of an era.
Addendum: Despite the official end of capitalism in Macau, it would become one of the strongest influences of special economic zones in Communist China, a gateway of foreign investment that would bring change of its own.
 In reality, followed by Japanese invasion of China in 1938, the neutral Portuguese officially occupied these three islands, with an excuse to better protect Portuguese missionaries residing there. In 1941, the Japanese Army threatened the Portuguese troops to force abandonment of these sparsely populated islands. Consequently, these islands were occupied by Japan. At the end of World War II, China was able to reoccupy the three islands.