The Keilians were (are) a large ethnic group of Noantri (exact numbers unknown, as they will not participate in a census) who occupy the Ausonian (Italian) peninsula, islands, and north coast of the Middle Sea. At the time of the Crossing, they had a non-industrial, medieval level of technology and culture. In the more than two hundred years since the Crossing, the Keilians have adopted only a few things from the more advanced Noantri cultures, such as firearms and in some places, electricity. They refuse to be part of modern culture, living outside of cities in villages and outposts. Their social structure is based on large clans which are perpetually at war or allied with each other in a complicated system of revenge and blood feuds.
The most interesting thing about the Keilians, from the mainstream point of view, is that the "ancient" Keilian society is actually fabricated. They are the result of a nostalgic "recreationist" movement among a group of Noantri in the old worlds. These groups, often academics, decided that they would rather live in a more "natural" way than as technical urbanites. They built a hypothetical society based on simulations they were already doing as role-playing, and eventually moved to uninhabited sections of known planets, or even new colonial worlds. There they divested themselves of the old culture and worlds and dropped back into the "past." More than a thousand years later, they were re-discovered by the Ingathering movement which brought the Noantri to New Earth, and they made the Crossing through the Gateway with the other Noantri.
After a while, a proportion of the Keilians, especially the ones near cities, have succumbed to the temptation of modern living and have adapted to the mainstream technology. In Surakosai, where Keilians dominate, they still stay away from high technology but do most of the construction and infrastructure building. Some have also become prosperous selling natural resource products such as timber, fish, minerals, and furs. Keilians live under a different legal system than other ethnicities in Surakosai; for instance, those accused of a crime still have the option of exonerating themselves by defending themselves in arena combat. These combats are open to the public and often attract big crowds.