North-South bias was used to describe southern Taiwanese people's feelings. The far-off reason is that Taipei started to grab leaders' attention by producing a large amount of profitable tea and camphor in Qing dynasty. In 1874, Japanese invaded Taiwan for the first time. Subsequently, leaders began to consider Taipei very important and established many government institutions. Subsequent to Treaty of Shimonoseki, the Japanese government located the ruling base in Taipei given Taipei had plenty of government institutions to take over, and its location that was closer to Japan than that of any other major city in Taiwan, making it easier to serve the Japanese; Taipei was the easiest place to conquer in Taiwan followed by the rest in northern Taiwan, unlike other regions of Taiwan that required Japanese soldiers to exert a great deal of forces for half a year to conquer, which some scholars from the south speculate led to the difference between the north and the south in culture and the way of thinking – they think northern Taiwan was more often than not occupied and ruled by an external races who then spread their own languages and cultures to northern Taiwanese. Some locals feel Taiwanese people's self-image has been distorted by various political authorities when looking back on the history of Taiwan. Some scholars from southern Taiwan thus consider the real inclinations of northern Taiwanese has been inhibited and believe themselves are the de facto pure Taiwanese. Generally speaking, Chinese immigration to northern Taiwan disposed local people with fewer things to identify with in their own environment.