Nation

One of the most influential doctrines in history is that all humans are divided into groups called nations.[citation needed] It is an ethical and philosophical doctrine in itself, and is the starting point for the ideology of nationalism. Members of a “nation” share a common identity, and usually a common origin, in the sense of ancestry, parentage or descent. A nation extends across generations, and includes the dead as full members. Past events are framed in this context; for example; by referring to “our soldiers” in conflicts which took place hundreds of years ago. More vaguely, nations are assumed to include future generations.

- Wikipedia: link.

See also United Nations.