Complex sentence: They were a tribal confederation and not a single political entity, each tribe had its own territory and were independent, and were also formed by smaller clans, however they had a cultural sense of unity and a common name for the tribes.
Split into simpler sentences: They were a tribal confederation, not a single political entity; each tribe had its own territory and was independent, and formed by smaller clans. However, they had a cultural sense of unity and a common name for the tribes.