This article attempts to trace the evolution of the concept of international mindedness from the 17th century until the present, using four aspects to focus the discussion: education and other trends, ease of interaction across frontiers, determinants of international mindedness, and international mindedness in practice. Education trends start with the lack of any reading and writing instruction for the masses in the 17th century through compulsory schooling much later--based principally on the drilling of facts and memorization--and then progressive education ideas including critical thinking skills and intercultural understanding. Trade/slave routes and discovery voyages by land and sea were the initial impetus for crossing frontiers, and it was not until the latter half of the 20th century that international telephone calls and airline travel started to be within the reach of larger parts of the world's populations. From the beginning of the 21st century, the Internet and free international communication by word and voice became a reality for many. Early determinants of international mindedness focused on students moving to similar schools in different countries at different stages of their secondary education. This later progressed in the mid 20th century to concepts of intercultural understanding, language learning and human rights, and in the late 20th century and 21st century to principles related to sustainable development, awareness of global issues, and international cooperation as conflicts continued to arise around the globe. The practice of international mindedness was rarely associated with developing a curriculum and pedagogical approaches that favoured intercultural dialogue, the realization of the inter-dependence of nations, and critical analysis skills. It manifested itself via student exchanges across frontiers, until the rise of international schools during the first half of the 20th century, which was the catalyst, during the 1960s, for the development of the first internationally minded programme to assist those schools: the International Baccalaureate Diploma. The article concludes with a list of components of international mindedness which have changed over time. (Contains 1 table, 1 figure, and 1 note.)