Why did pirates and foreign powers attack Ribeira Grande?

Ribeira Grande (now Cidade Velha) became a target for pirates and foreign powers primarily due to the significant wealth and prosperity it accumulated as a central hub in the transatlantic slave trade.1

As an offshore entrepôt, the city served as a critical node in the triangular trade, facilitating the exchange of slaves, ivory, gold, and valuable pano cloths. This concentration of resources and the city's role in the lucrative trade network attracted hostile attention from those seeking to challenge the Portuguese monopoly on West African commerce.1

Consequently, the city faced multiple incursions:
* 1541: Attacked by pirates.1
* 1585 and 1592: Attacked by the English, with the former led by Sir Francis Drake.1
* 1712: Attacked by the French, which ultimately prompted the relocation of the capital to Praia.1