proper. The Kingdom of Mbundu in the south and the BaKongo in the north were always at odds, but Kongo managed to exact tribute from these states since before the colonization by the Portuguese. Seeds of independence In 1518 the Kingdom of Ndongo sent an embassy to Portugal asking for missionaries and (indirectly) for recognition as independent of Kongo. A Portuguese mission arrived in Ndongo in 1520 but local disputes and perhaps Kongo pressure forced the missionaries to withdraw. Afonso I of Kongo took the missionaries to Kongo and left his own priest in Ndongo. War of 1556 Around 1556 Ndongo sent another mission to Portugal seeking military assistance and offering to be baptized, even though Portuguese officials at the time were unsure of the religious sincerity. In 1901, historian E.G. Ravenstein claimed that this mission was the result of a war between Kongo and Ndongo, in which Ndongo won and claimed its independence, which was also claimed by historian Jan Vansina in 1966 and then others, but this appears to have been a misreading of the original sources. Ndongo may well have seen the mission as a sort of declaration of independence since Kongo's response to the 1518 mission suggests that it still maintained sufficient control to prevent it being an independent move. The second Portuguese mission arrived at the mouth of the Cuanza River in 1560, headed by Paulo Dias de Novais, grandson of the famous explorer Bartolomeu Dias, and including several Jesuit priests including Francisco de Gouveia. This mission also failed and Dias de Novais returned to Portugal in 1564, leaving Gouveia behind. The Portuguese colony of Angola By the time of the third mission in 1571, the King of Portugal Sebastian I had decided to charge Dias de Novais with the conquest and subjugation of the "Kingdom of Angola", authorizing him to govern the region, bring in settlers, and build forts. Dias de Novais arrived in Luanda by arrangement with Kongo's king Álvaro I in recompense for Portugal's assistance against the Jaga. Quilongo, the king of Angola, renewed the connection with Portugal in 1578. Unable to conquer any territory on his own, Dias de Novais made alliances with both Kongo and Ndongo, serving as a mercenary army. The First Portuguese-Ndongo War In 1579, Portuguese merchants who had settled in Kongo, led by Francisco Barbuda, advised Njinga Ndambi Kilombo kia Kasenda that Portugal intended to take over