In the year 1309, Portugal decided to build its own colony after seeing the Castilian colonies gain a lot of gold and other wealth. They sent an explorer, Arquelao Soto Posada, to explore and conquer the region. After returning with a fabled amount of gold, the Portuguese king of the time named the region Costa Dourada (Golden Coast).
Over the next few years, instead of spreading quickly, the Portuguese build a few settlements and worked on building them up. The Castilians were spreading three times as fast as them, but had many people dying to natives.
Soon after this, however, Castile and Aragon united, merging their colonies and soon making Costa Dourada unable to expand. In 1415, the Portuguese turned over their colonies to Castile-Aragon, due to them being afraid of the skirmishes near the border. They believed that there could be all out war.