Anne Hilton's The Kingdom of Kongo offers a broad overview of the Kingdom of Kongo's rise and fall based on local adoption and adaptation of Christianity, Atlantic trade, and slavery in West Central Africa. Relying on, for the most part, written sources and some 20th century ethnographies, Hilton suggests the origins of Kongo lay in a redistributive economic system in which goods produced by distinct ecological zones of the Kongo state were exchanged. The mani kongo, or king, emerged sometime by the early 15th century as the dominant figure in this system, controlling the redistribution of local cloth, salt, nzimbu shells, and copper from beyond the borders of Kongo. The early state, however, was built on 3 distinct religious dimensions and different kinship structures, including matrilineal kanda and what later emerged as patrilineal groups based on descent from the daughters of Afonso I.
However, the early Kongo state was relatively decentralized and the kings were eager to find new sources of legitimation. The mbumba, nkadi pmemba, and kitome dimensions were all important, but the Catholic cult and its association with the mani Kongo and aristocratic Mwissikongo aristocrats provided a religious or spiritual source of legitimacy that connected the kings with the cult of the ancestors and the sky spirits. While it is perhaps debateable to what extent this cosmovision really influenced the way Afonso I adopted Catholicism, Kongo was accepted as a Christian state by Europeans and adopted literacy, some Portuguese names, and even tried to buy or purchase European-styled ships. The kings of Kongo and the Mwissikongo supported the new religion, used literacy to enhance administration, accepted new crops from the Americas, and took advantage of the copper, slave, and nzimbu trades to expand Kongo's power in West Central Africa. Indeed, Kongo's cloth production was central to the currency and trade of the Portuguese colony of Luanda and Portuguese slave trading in the interior.
Unfortunately for Kongo, however, Catholicism and the centralization achieved by Afonso, Diogo I and Kongo kings until the early decades of the 17th century was challenged by new developments. Sonyo, a province of Kongo, became increasingly independent and weakened Mbanza Kongo's economic importance through new trade routes with the Vili and others. Instead of the old Makoko-Mbanza and Luanda trade routes for slaves, ports like Mpinda and alternative slave routes developed that bypassed Kongo or did not rely on Kongo's cloth. In addition, Portuguese expansion of the Luanda colony and the seizure of the nzimbu-producing Kongo territory, as well as attacks on vassal states or chiefdoms of Kongo, further weakened Kongo. The Kongo kings were also not successful with establishing complete control of the Catholic Church, an institution which was central to the further legitimation of the rulers. The Portuguese refused, despite Afonso I's son serving as a bishop, allowing for an independent see of Mbanza Kongo and the clergy, prefects, and priests in Kongo were often dictated by or led by men based in Luanda. Even the Capuchins, who came to Kongo and were initially seized upon by Garcia II to strengthen his rule, eventually became more aligned with Luanda while criticizing the state of Christianity in the Kongolese provinces. Even the Dutch occupation of Luanda was a failure in the sense that Kongo did not eradicate the Portuguese presence and, in fact, was blamed for anti-Portuguese massacres. The enmity between Kongo and Luanda governors, who could also block envoys and letters from Kongo to the Pope or to Spain and Portugal, eventually led to the fateful battle of Mbwila.
The later centuries of Kongo cover its existence as a splintered or fragmented state, with autonomous provinces like Sonyo and warlods and competing lineage groups competing for the throne. Kongo Catholicism survived, even leading to a site of pilgrimage devoted to the Virgin Mary and the close relationship between Mwissikongo and the Christian cult. Kongo indigenous religion likewise continued, even experiencing a revival during the reign of Garcia II and that of his son due to Capuchin aggression Nonetheless, the Kongo of the 18th and 19th centuries was very different from the state system consolidated by Afonso I and his successors. While the Portuguese and the trans-Atlantic Slave Trade did not destroy Kongo, one can undoubtedly see how Atlantic trade was a double-edged sword that paved the way for Kongo centralization and decentralization. The main reason why Kongo, however, was not able to maintain its dominant position was related to its increasingly peripheral role in the main trade routes used for the slave trade and the decline of the mani Kongo's role in redistributing regional or international goods to his clients. The failure to establish a church under royal control further undermined the Kongo kings since one of the major ideological sources of their legitimacy was controlled by external actors not always acting in the interests of Kongo or its state.