Keşifler çağı'nın ilk yüzyılında Portekizliler (1415-1499)

The period that is considered to have started in the first quarter of the 15th century and to have ended in the second half of the 17th century is called the Age of Discovery. In the Age of Discovery, some European states explored the unknown lands of the world through overseas expeditions, established commercial and diplomatic relations with the indigenous peoples of the discovered lands, and waged wars. Although this is one of the most important topics of history, unfortunately, not having been shown sufficient interest and not conducted much study in our country. In our study to draw the attention it deserves, we addressed the military, commercial and diplomatic activities of Portugal, the state that started the Age of Discovery, in the 15th century. Although the Portuguese had important overseas activities that continued in the 16th century, especially in Asia and Brazil, it was considered appropriate to limit our work to only the 15th century in order to focus on a specific period. Since there is a lack of Turkish books in this field, various foreign sources have been used and resources have been translated from English to use in our thesis. In the first chapter, the introduction chapter, trade, technology, maps, previous voyages and the status of Portugal before the 15th century are explained. The second chapter discusses the Portuguese activity in Northwest Africa, and in particular their relations with the Moroccans. In chapter three, exploration and residential activities in the islands of the Atlantic Ocean is specified; chapter four depicts their exploration and trade activities and enslavement raids in Africa, especially in the Guinea region; chapter five depicts their passage to Asia and Vasco da Gama's expedition to India. The sixth and final chapter discusses the military, technological and commercial structures of the Portuguese state in the 15th century.