triggering cholera and tuberculous outbreaks. Dysentery, typhoid, and malaria were also rife. The city doctor Willem T. de Vogel advocated strenuously for reducing overcrowding and improving living conditions by extending Semarang into the less malarial hill country to its south; his fellow councilman Hendrik Tillema had campaigned on a platform of combatting malaria and joined De Vogel's scheme, broadening it into a "village improvement" () movement. Purchasing land in the heights with their own money, the two men and some friends passed it on to the city with an initial zoning plan by KPC de Bazel in 1907 but could never convince a majority of the council to support its development. Changing tack, Tillema then worked to improve the existing kampongs in the city's malarial districts by improving drainage and providing more sanitary public toilets and public housing. A decade later, the town approved Thomas Karsten's revised plan for the area, using it to build larger villas for the Dutch and wealthy Chinese and Javanese rather than allowing its use by the poor. This area became known as Candi Baru () and forms the core of the present-day Candisari District. Although it remained highly stratified by class, Candi Baru had less ethnic segregation than the older area of town and incorporated public squares, athletic facilities, and places for public bathing and washing that could be used communally. With most work remaining in the lower city and transportation slow or expensive, few of the lower classes were interested in moving to the district but it set a pattern that was followed with three more successful housing plans between 1916 and 1919. The population grew by 55%, adding 45,000 Javanese, 8500 Chinese, and 7000 Europeans. Karsten's approach to town planning emphasized its aesthetic, practical, and social requirements articulated in economic terms rather than purely racial ones. Driven by economic growth and spatial city planning, the city had doubled in size and expanded to the south by the 1920s, creating a nucleus of a metropolis where multi-ethnic groups lived and traded in the city. The villages in the suburbs such as Jomblang and Jatingaleh steadily became the satellite towns of Semarang, more populated with a bigger market area. Before the invasion of Japan in 1942, Semarang had already become the capital of Central Java province, as the result of trade and industrial success and spatial planning. Japanese occupation and early independence The Japanese