How did The Portuguese destroy Kongo during the seventeenth century?

The kingdom went into decline from the mid-16th century CE when the Portuguese, put off by the interference of Kongo's regulations on trade, moved their interests further south to the region of Ndongo. The latter kingdom had already defeated a Kongo army in 1556 CE

Explanation:

b: the establishment clause  

b: socialism  

a countries leader should be motivated by the common good of the country.