However, Dutch authorities came to realize that they could not monopolize the slave trade from Angola just by holding Luanda and a few nearby places, and moreover, the Portuguese sent several relief expeditions to Massangano from Brazil.
Namun, pemerintah Belanda menyadari bahwa mereka tidak dapat memonopoli perdagangan budak dari Angola hanya dengan memegang Luanda dan beberapa tempat di dekatnya, dan terlebih lagi, Portugis mengirimkan beberapa bantuan ekspedisi ke Massangano dari Brasil.