So once the Portuguese breached the Indian Ocean, they didn't create, like, huge colonies, because there were already powerful empires in the region. Instead, they apparently sat in the middle of the Indian Ocean doing nothing. Actually, they were able to capture and control a number of coastal cities, creating what historians call a trading post empire. They could do this thanks to their well-armed ships, which captured cities by firing cannons into city walls like IRL Angry Birds. But since the Portuguese didn't have enough people or boats to run the Indian Ocean trade, they had to rely on extortion. So Portuguese merchant ships would capture other ships and force them to purchase a permit to trade called a cartaz. And without a cartaz, a merchant couldn't trade in any of the towns that Portugal controlled.