As citizens of modern Southeast Asia, we often take for granted nation-state that in fact is a new concept. Not only it is contemporary, border that demarcate states both on water and land is innately artificial and porous. Department of History, Faculty of Cultural Sciences UGM initiated “International Summer School on Southeast Asian Studies; Transnational History: Becoming a Cosmopolitan Historian” to promote perspective that transcends border for young and potential researchers. The summer school took place at Faculty of Cultural Sciences Universitas Gadjah Mada from 27th August– 6th September 2018. Participants of this summer school are undergraduate and graduate students as well as young lecturers from Australia, Japan, Malaysia, Thailand, United States, and Vietnam. This summer school also incorporates Indonesian students from state universities throughout the country.