•Why it earns a slot
The first work in the Western tradition to treat recent human events as a subject worth investigating and recording systematically, earning Herodotus the title 'Father of History' from Cicero five centuries later.
Herodotus set out to record the causes of the Greco-Persian Wars before living memory of them faded, and in doing so wrote the first surviving work of history as a genre distinct from myth or epic poetry. He mixes real reporting with folklore and legend freely, opening with competing myths about who started the conflict between Greece and Persia before settling on the historical figure he can actually pin blame on: Croesus of Lydia.
This distillation is written from the freely available original, which is always the better read when you have the time: Project Gutenberg.