Strata

A history of the whole human past told as a single spine: six mineral strata of time, from the deep past to the twentieth century, each its own era colour, read downward as if you were drilling a core sample.

It exists to give scattered history a shape you can hold. Six through-line forces run the length of it, and a 'how we know' note is honest about where the record is thin.

What to take from it: choose a governing metaphor and commit. The core-sample idea — cool slate rock rather than the parchment cliché — turns a list of centuries into a single readable object.