The history of the Kongo is an ancient and complex one, and can be traced back as early as the 13th century, arriving at their present location from the north. The Kongo were early targets of Christian converters, and while some adopted the religion, large numbers did not. This of course created tension, and resulted in rival factions. The Kongo, well-organized and large in numbers, expelled the Portuguese in 1526, only to be invaded by the Jagas in 1568. The Kongo were thus forced to ask the Portuguese for assistance. Thus began the slow decline of the Kongo Empire. Though they fought both for and against the Portuguese in the years that followed, they were formally colonized in 1885. Independence from Portugal was finally attained in 1960, under the leadership of the Abako party. The arts of the Kongo, and those of many of the peoples living near the mouth of the Congo River, though primarily thought of as a court art, are nonetheless dominated by imposing power figures produced for personal and group use, for a variety of purposes, from healing to protection, both real and imagined. The Kongo are also well-known for carved funerary and maternity figures, often of great beauty and expressiveness. While not as common as figures, the Kongo produce some wonderful masks, used in initiations. They often have the same wide-eyed, haunting appeal as the maternity and funerary statues. The best of these are, like the statuary, considered among the great masterpieces of African art. Like the figures, masks of the Kongo and Yombe are very similar, in both use and appearance. The Kongo produce an array of prestige items, in a variety of materials, from ivory to stone to metal, and these are also highly-prized by collectors. The art of the Kongo has assumed a special place in the hearts of serious collectors worldwide.