Historically, Soyo was a significant city in conflicts between the Kingdom of Kongo, Portuguese Angola, and the Dutch West India Company.

Soyo was typically ruled in the sixteenth century by a member of Kongo's royal family, presumably appointed by the king and serving for a limited term.

This expansion allowed Soyo to control several sub-provinces including Pambala, Kimi, Tubii, along the Congo River, and Lovata (among others) along the Atlantic coast.

A Kongo royal inquest of 1548 revealed that as many as 4,000 slaves passed through Mpinda en route to the island colony of São Tomé, and then to Brazil every year.

He was, however, not entirely supportive of Álvaro's ambitions and there was a long period of considerable tension between Kongo and Soyo, resulting in the recognition of Miguel as a more or less independent ruler.

The king of Kongo invaded the area, killed da Silva's son, and installed Pedro Afonso Nkanga a Mvika, who previously was Marquis of Wenbo, as Duke of Soyo.

Counts of Soyo protected them and gave them refuge, as they did in 1656 when a conspiracy to overthrow Garcia organized by sons of Pedro II failed.

[6] In the 1680s Antonio II Baretto da Silva, the count of Soyo waged war with Kakongo and Ngoyo, the kingdom's to the north of the Congo River.