The aim of this chapter is to tell the stories of how and why these new parties were established. Naturally, I will tell the story of how the GPT was established in early 1996 in the run-up to the National Assembly elections, but I will also discuss the establishment of a party that split away from the GPT in 2014, the Trees Party. I will address the first of the book’s ‘why’ questions, that of how best to understand the formation of these new parties. Thus, the focus is on the process up to the threshold of declaration on my party lifespan framework, leaving the post-establishment elections and issue campaigns for subsequent chapters. There is a rich literature on what explains new party or movement party formation, and so I am interested to see how these two cases fit in those frameworks. Similarly, from a comparative perspective, did the formation of the Green Parties in Taiwan follow similar or different patterns from those of ecological parties in other countries?