The earliest archeological evidence is from Tchissanga (now part of modern Republic of the Congo), a site dated to about 600 BCE. However, the site does not prove which ethnic group was resident at that time. The Kongo people had settled into the area well before the fifth century CE, begun a society that utilized the diverse and rich resources of region and developed farming methods. According to James Denbow, social complexity had probably been achieved by the second century CE.