This chapter explores on a study of Macau's urban transformation from its sixteenth-century foundation until its hand-over in 1999, covering nearly 450 years of Portuguese presence in Macau. It focuses on the period preceding the Sino-Japanese War and Second World War, that is, from 1927 until 1949, that was marked by the impact of the late 1920s 'grand planning' ethos. Macau's urban transformation was linked to the uncertain political state of affairs of Portugal and China. At the end of the nineteenth century, Portugal's interests in Macau were shifting from a mercantile intent towards a politico-diplomatic role, and to urban development as a means of economic endurance. Sixteenth-century Portuguese urbanism culture entailed a strong adaptation to local contexts, so the spatial patterns created across its settlements globally were diverse. Macau was indeed a unique urban interface for East and West civilizations, and individuals came to Macau for diverse reasons, but primarily due to political and economic interests.