Why did Columbus and Cartier display symbols of their countries as they landed in the New World?

Columbus and Cartier displayed symbols of their countries upon landing in the New World to assert sovereignty and claim the territory for their respective nations, Spain and France. This act served to legitimize their explorations and demonstrate their nations' power and presence in newly discovered lands. By raising flags and other national symbols, they aimed to establish a sense of ownership and encourage further colonization efforts. Additionally, it was a way to communicate to indigenous peoples that they were entering a new era of exploration and conquest.