According to Tsao Yung-ho, of the History Department at National Taiwan University, Taiwan's only authority on old European maps and a fluent speaker of Dutch, the earliest known western diagram of Taiwan is on a world map made in 1554 by Lopo Homen, a Portuguese cartographer.
精通荷蘭語的台灣大學歷史系兼任教授曹永和，是目前台灣唯一對歐洲古地圖有研究的人。他指出，目前所知最早出現台灣島的歐洲古地圖，是一五五四年葡萄牙製圖家羅伯．歐蒙所繪的世界地圖。