The three European kingdoms that became major colonial powers through exploration were Spain, Portugal, and England. The document discusses the "3Gs" that drove European exploration: God (spreading Christianity), Gold (acquiring wealth), and Glory (expanding national power and prestige). It then summarizes the early Spanish expeditions to the Philippines led by Ferdinand Magellan, Alvaro de Saavedra, Ruy Lopez de Villalobos, and Miguel Lopez de Legazpi, who established the first Spanish cities in the Philippines.